WHAT THE DATA SAYS · 02

K League 1 2026 · FC Seoul · 25 matches · 34,518 events

Seoul do not do more. They score more.

They are a possession side — 56.0%, short out of the back. But the further forward they go the wider they are pushed: 82% of their entries into the final third come down a channel, 66% of their deliveries into the box are crosses, and 46.5% of those crosses are cut out in front of the box. The volume of chances they build is level with the league's 2nd and 3rd best. The points are 15 clear. The difference is made at the last touch.

Han HyukjinSeptember 2026Data: K League Data PortalWhat the data says — part 2

The conclusions first

Fifth for volume, first for results. 12.0 shots (5th), 468.5 passes (5th) and 23.0 tackles (5th) produce 53 points (1st, 15 clear), 19 goals conceded (fewest) and 12 clean sheets.
They hold the ball, and the more they hold it the worse it goes. 56.0% on average. 2.40 points a match in the ten games at 51% or below; 1.88 in the eight at 60% or above. Three of the season's four defeats came in the 60s.
The further forward, the wider. Final-third entries split 40 left, 18 centre, 42 right (opponents put 25 through the middle). Of 878 deliveries into the box, 66% are crosses.
Of 579 crosses, 108 (18.7%) became a shot and 269 (46.5%) were cut out. Seoul win 38% of their aerial duels inside the opponent's box.
So the volume of chances is ordinary. 36.86 xG — level with Jeonbuk's 36.77 and Ulsan's 36.06 — and an xG difference of +0.41 a match.
The difference is made at the last touch. 43.5% of shots on target become goals, first in the league against an average of 31.0%; the teams facing Seoul manage 23.2%. Regress both to the average and the goal difference falls from +28 to +8.
It held for all 25 matches. Goals/xG 1.15 → 1.19, conceded/xG against 0.68 → 0.72. But 25 matches is not enough to separate skill from variance.

1Where Seoul stand in the league

Start with how much of everything they actually do

Seoul have 53 points from 25 matches. Jeonbuk, second, have 38. That is a 15-point lead. Per match it is 2.12 against 1.52 — 39% more than the side behind them. Their 19 goals conceded is the fewest in the league, and 12 of the 25 were clean sheets.

Look at the volume, though, and no such gap exists. 12.0 shots a match — 5th in the league. 468.5 passes — 5th. 23.0 tackles — 5th. 50.1 duels — 6th. Their shot count is 86% of Jeonbuk's league-leading 13.8. Good numbers, but nothing that dominates a division.

Figure 1 · Seoul's rank, metric by metric. Each dot is where they sit among the 12 clubs. Points, goals against, conversion of shots on target and fouls won cluster at 1st; the volume metrics — shots, passes, tackles, duels — sit at 5th and 6th. At the bottom, interceptions 12th (last) and offsides 11th, both dealt with in §9. Hover a dot for the figure.

This piece follows that gap. How does a side that ranks 5th for volume finish 15 points clear?

2They are a possession side — and the more of it they have, the worse it goes

56.0% of the ball on average, and points that move the other way

Across the 25 matches Seoul played 12,340 passes to their opponents' 9,406, averaging 56.0% possession and dropping below 50% in only five games. They are a possession side. Their possession phases — one team's spell until the opponent registers two consecutive events — average 5.02 passes against 3.80, and end in a shot 11.3% of the time against 8.7%.

Split the season by possession band, though, and the direction is not the expected one.

Figure 2 · Possession and result, match by match. One dot per match, coloured by result. The three groups underneath are the possession bands — 2.40 points per match in the ten games at 51% or below, 1.88 in the eight at 60% or above. In the high-possession games they build more shots (16.4) and more xG (1.90), and concede more (1.25) for fewer points. ⚠ There is reverse causation in this — trailing gets you the ball. But the fact that Seoul also built more in those matches is not explained by chasing alone.

Across all 25 matches the correlation between possession and points is −0.18. The only quantity that tracks points is xG, at +0.44.

3Short at the back, wide at the front

The way they carry the ball is clear; where it arrives is lopsided

Passes leaving their own deep third (below X 15 in attacking direction) average 23.5m, with 25% travelling 30m or more. Their opponents, from the same area, average 28.4m and 36%. Seoul do not clear their lines long. They complete 79% of those passes against 73%.

What follows is the problem. Split the 1,212 passes into the final third by channel and it reads 40% left, 18% centre, 42% right. Their opponents put 25% through the middle in the same phase. Seoul do not enter centrally. 82% of their entries go down a channel.

Figure 3 · Entry channels and deliveries into the box. The figures on the left are the channel split of passes into the final third. On the right, the 878 deliveries into the box (35.1 a match), of which 66% are crosses. Where their passes end up by third is almost identical to their opponents' (own third 24 v 26, middle 46 v 44, final third 18 v 17, around the box 13 v 13) — the difference is not how far they carry it, but which way.

4Half the crosses end in front of the box

4th in the league for delivery, and the delivery does not end well

Seoul cross 23.3 times a match, 4th in the league — 579 across the season. Count how those 579 ended: 108 (18.7%) became a shot, and 269 (46.5%) were cleared or blocked. One in five turns into a shot; one in two is cut out in front of the box.

Figure 4 · How the crosses ended, and aerial duels by zone. The right-hand panel carries part of the reason: Seoul win 38% of aerial duels inside the opponent's penalty area and 31% in the six-yard box. In their own defensive third they win 56%. Two-thirds of their deliveries into the box are crosses, and they lose the contest where those crosses land. ⚠ An aerial win rate is made jointly by the opposing defenders' height and positioning and by the quality of the cross; this data cannot separate the two.

The same holds at phase level. Of the 643 possessions that put a ball into the box, 153 (23.8%) produced a shot, and the xG per possession is 0.035. They get the ball in there often; each occasion is not worth much.

5So the volume of chances they build is ordinary

On xG, Seoul are not out on their own

On the portal's official model Seoul's season xG is 36.86. It leads the league, but Jeonbuk's 36.77 and Ulsan's 36.06 are effectively the same number. Their xG difference per match (Seoul minus opponent) is +0.41 — small for a side 15 points clear.

They scored 47. That is +10.1 goals above the model, the largest surplus of the 12 clubs and clear of second-placed Anyang (+7.2).

Figure 5 · Season xG against goals scored. The dashed line is where a side scores exactly what its chances were worth; above it is a surplus, below it a shortfall. Seoul, Jeonbuk and Ulsan all sit in the 36s for xG and finish on 47, 31 and 38 goals. ⚠ xG is a model's score for the position and circumstances of each shot, and models disagree. This is the portal's official model; summing the event feed directly gives 37.64.

6The difference is made at the last touch

How often a shot on target becomes a goal — and the same figure at the other end

Seoul scored 47 goals from 108 shots on target — 43.5%. The league average is 31.0%; second-placed Incheon are on 34.8%. The gap from Seoul to second is 8.7 points; from second to last-placed Gwangju (19.2%) it is 15.6. Seoul are on their own.

The other end points the same way. The teams that played Seoul put 82 shots on target across those 25 matches and scored 19. That is 23.2%, 7.8 points below the league average. The goalkeeper, Ku Sungyun, played all 25 matches and all 2,602 minutes.

Figure 6 · How often one shot on target becomes a goal. Above, the 12 clubs' attacking conversion; the red bar at the bottom is the same figure for the teams facing Seoul. ⚠ Even inside the portal, "shots on target" is counted differently by different systems. Every club here is computed on the supplementary-records system so the twelve are comparable (the official-records system puts Seoul at 148). The values shift with the system; the order does not.

Put in numbers

Had Seoul converted at the league's 31.0%, 108 × 0.310 = 33.5 goals — 13.5 fewer than they scored. Had their opponents converted at the same rate, 82 × 0.310 = 25.4 conceded — 6.4 more than they allowed. Put the two together and the goal difference falls from +28 to +8.

⚠ This is arithmetic on goal difference, not a projection of points. Which matches the goals fall in changes the table completely. All it establishes is the size of the gap.

7If it were luck, it would not have lasted 25 matches

Which is not the same as calling it skill

The first thing to doubt about a high conversion rate is the sample. A two-month hot streak should have collapsed by the second half of the season. So split the season in two.

Figure 7 · First half of the season against the second. Goals/xG went 1.15 → 1.19, and conceded/xG against 0.68 → 0.72. Both held; neither collapsed. What also stands out is that xG against per match fell 40%, from 1.36 to 0.81. That is a sign of opponents dropping off against Seoul — and it is the other face of what §2 showed, that the more of the ball they get, the less it goes their way.

⚠ Twenty-five matches is not enough to settle a conversion rate. Swings of this size occur inside a single season from chance alone. That both halves held weakens the chance explanation; it does not rule it out. Equally, what the xG model cannot see — the pressure on the shooter, where the keeper was standing, which corner was chosen — may account for part of it. This piece does not decide between them. It can leave a testable prediction: if it is luck, it comes back over the remaining rounds.

8This team's clock

Thirty per cent of the season's goals sit in the quarter-hour after the break

Figure 8 · xG and goals across six bands. Seoul on the left, opponents on the right; the two figures at the far right are actual goals for and against. Between the 46th and 60th minute they scored 14 and conceded 2. The xG, 9.86 to 3.28, is also the largest of any band — here they were ahead on the play as well as on the finishing. After the 76th minute is the one band they trail, 9.63 to 9.73. (The official records put 15 goals in the first quarter-hour after the break; the one-goal difference from the event feed's 14 is an own-goal tagging.)

The foul counts move with the clock too. Fouls won by Seoul go 46, 41, 41 across the first half and 55, 53, 57 across the second; fouls they commit fall from 45 and 48 early on to 31 and 36 in the middle of the second half. The longer a match runs, the less Seoul foul and the more they are fouled.

Hwaseong FC, part 1 of this series, also scored 10 and conceded 1 between the 46th and 60th. Whether the two happen for the same reason cannot be told from this data. Different divisions, and Hwaseong average 45.7% possession against Seoul's 56.0%. What happens right after half-time is a question worth putting to the whole of the K League separately.

9The defence — few interceptions, few fouls, 19 conceded

The league's meanest defence posts oddly low defensive numbers

Seoul make the fewest interceptions in the league (7.4 a match; Daejeon lead on 10.4) and rank 11th for offsides (1.04). Tackles 5th, blocks 5th, duels 6th — the rest is unremarkable. Their defensive actions average X 38.9 in attacking direction against their opponents' 36.7, barely higher. This is neither a high press nor a low block.

What does stand out is the fouls. They commit 10.2 a match — third-fewest — and win 12.3, the most in the league. The difference of +2.1 is unmatched; the league average is −0.6.

Figure 9 · The foul economy. Fouls committed on the x-axis, fouls won on the y. Top-left is "commit fewer, draw more", and Seoul are alone in that corner. ⚠ What produces this the data does not say. It could be that keeping the ball leaves less to foul over, or that the dribbling (2nd in the league) draws contact, or that it is a by-product of refereeing tendencies and the shape of their matches.

A mirror image of Hwaseong in part 1. Hwaseong were first in their league for offsides and last for duels — a side that runs at the space behind. Seoul are 11th for offsides and first for fouls won — a side that keeps the ball at its feet and draws opponents onto it. Both sit at the top of their divisions by opposite means.

10The performances are not dominant

Seoul were behind on xG in 12 of the 25

Figure 10 · xG difference and result, match by match. xG difference (Seoul minus opponent) runs left to right; the three rows are wins, draws and defeats. The green band holds the five wins with the xG against them — R1 Incheon 2-1, R2 Ulsan 4-1, R4 Pohang 1-0, R10 Gangwon 2-1, R15 Daejeon 2-1. In the other direction there are two defeats with the xG in their favour (R8 Daejeon 0-1, R20 Ulsan 1-3). Hover a dot for that match's figures.

In the eight matches with the largest xG difference Seoul went eight from eight (3.00 points a match); in the bottom eight they averaged 1.50. When the performance is good they win it; when it is poor they still salvage half. That half is the 15-point lead.

11Where the 47 goals came from

Almost nothing from set pieces, and the surplus concentrated in one player

By type: 18 from an open-play pass along the ground, 12 unassisted, 11 from an aerial delivery in open play. That is 41 goals, 87% of the total, from open play. Two from corners, two from free kicks, one penalty, one opposition own goal. They win 5.2 corners a match, second in the league, and have taken 129 for two goals — which reads as the same story as the 38% aerial win rate inside the box from §4.

The finishing zones cluster very close to goal: 11 from the middle of the six-yard area, 7 from its left side, 6 from its right, 5 from the penalty spot area. 63.9% of all their shots come from inside the box, second in the league.

Figure 11 · Goals scored minus expected goals, by player. Jung Seungwon scored 8 from 3.96 xG — a +4.04 surplus, 40% of the team's total. The leading scorer, Klimala, has 9 goals from 8.84 xG, almost exactly what the chances were worth: the top scorer is not the source of the surplus. ⚠ An individual's xG surplus rests on a far smaller sample than a team's. Jung's 3.96 is every shot he took all season, and a +4 on a sample that size occurs by chance. One season cannot establish that a player finishes well.

12Four matches that show this football

All of the ball · level on the play · everything went in · and the day it tipped back

R25

Seventy-one per cent of the ball, one goal

1-0H · Bucheon

The season's highest possession share, 71%. Seventeen shots. One goal, off 1.48 xG. Bucheon were held to five shots worth 0.37, so the result is flawless — but this is what the side looks like when it has all of the ball: knock seventeen times, get in once. Across the eight matches at 60% or more they average 16.4 shots and 1.75 goals.

Watch for — Where Seoul enter once the opponent has dropped off — and why sixteen of the seventeen went nowhere.

71%possession (season high)

17shots

1goal

1.48xG

Twenty-five shots conceded, won 4-1

4-1A · Ulsan

Ulsan took 25 shots, the most Seoul allowed in any match all season. The xG finished 2.74 to 2.71 — level, to all intents. The scoreline finished 4-1. Four goals from Seoul's thirteen shots; one from Ulsan's twenty-five. Possession was an ordinary 51%. Behind on the play, ahead on the scoreboard — the side's defining trait in a single afternoon.

Watch for — What happened at each end. Not how many shots, but how the shots finished.

2.71 v 2.74xG — level

25Ulsan shots

4-1final score

51%possession

R24

The day everything went in

7-0A · Anyang

Seventeen shots, 2.62 xG — and seven goals. 2.7 times what the chances were worth. This one match built almost half of the season's +10.1 surplus over xG. Anyang were held to four shots worth 0.28. It shows both what the side looks like at its best and how abnormal the gap is, in ninety minutes.

Watch for — What has to be different for the same xG to produce seven goals. Watch where each shot finished.

2.62Seoul xG

7goals

2.7×goals ÷ xG

0.28Anyang xG

R20

The day it tipped the other way

1-3H · Ulsan

Seventy per cent of the ball, seventeen shots, xG ahead 1.59 to 1.31. Lost 1-3. Three of the season's four defeats came in matches with 60% or more possession (R11 60%, R13 67%, R20 70%). Trailing gets you the ball, so some of that is circular — but in those matches Seoul also built more shots and more xG. They built it and lost anyway.

Watch for — How a match won on the numbers is lost. And how the space behind opens once the line goes up.

70%possession

+0.28xG difference

1-3result

3 of 4defeats at 60%+

R	H/A	Opponent	Result	Poss	Shots	xG	Opp sh	Opp xG	xG diff
24	A	Anyang	W 7-0	56%	17	2.62	4	0.28	+2.34
9	H	Bucheon	W 3-0	64%	13	3.06	10	1.19	+1.87
19	H	Pohang	W 3-1	43%	15	2.50	7	0.78	+1.72
23	H	Daejeon	W 4-2	59%	17	2.73	13	1.06	+1.67
3	A	Jeju	W 2-1	63%	15	2.43	9	0.86	+1.57
5	H	Gwangju	W 5-0	50%	11	2.08	8	0.51	+1.57
14	A	Gwangju	W 1-0	60%	22	1.66	3	0.20	+1.46
25	H	Bucheon	W 1-0	71%	17	1.48	5	0.37	+1.11
7	H	Jeonbuk	W 1-0	55%	7	1.30	7	0.41	+0.89
18	A	Bucheon	W 3-1	68%	17	2.25	13	1.48	+0.77
20	H	Ulsan	L 1-3	70%	17	1.59	8	1.31	+0.28
8	H	Daejeon	L 0-1	57%	10	1.46	8	1.33	+0.13
16	H	Incheon	W 1-0	46%	6	0.55	6	0.55	+0.00
15	A	Daejeon	W 2-1	51%	10	0.79	9	0.80	-0.01
2	A	Ulsan	W 4-1	51%	13	2.71	25	2.74	-0.03
12	H	Anyang	D 0-0	48%	7	0.69	6	0.77	-0.08
22	A	Gimcheon	D 0-0	44%	5	0.56	7	0.67	-0.11
6	A	Anyang	D 1-1	55%	8	0.35	7	0.64	-0.29
11	H	Gimcheon	L 2-3	60%	14	1.12	11	1.42	-0.30
1	A	Incheon	W 2-1	43%	11	1.06	8	1.42	-0.36
17	H	Gangwon	D 0-0	59%	7	0.52	11	1.12	-0.60
21	A	Jeonbuk	D 0-0	51%	7	0.36	14	1.07	-0.71
4	A	Pohang	W 1-0	58%	8	1.36	12	2.08	-0.72
13	A	Jeju	L 1-2	67%	16	1.60	11	2.43	-0.83
10	A	Gangwon	W 2-1	50%	5	0.83	17	1.83	-1.00

All 25 matches, sorted by xG difference. The four highlighted rows are the ones above. xG is summed directly from the event feed; possession comes from the official match records.

13So what should be watched

If you are facing them

Win the ball in the air inside your own box. Two-thirds of Seoul's deliveries are crosses and they win only 38% of the aerial duels there. 46.5% of those crosses are already cleared or blocked.
The 46th to 60th minute. Thirty per cent of their goals sit there, and so does their largest xG band — this is a stretch where they are better, not just luckier.
After the 76th minute. The one band where they trail on xG (9.63 to 9.73). Opponents have already taken six goals there.
Out-shooting them is not, by itself, a plan. Ulsan took 25 and lost 1-4; Gangwon took 17 and lost 1-2. It is not the count that matters but the quality of what reaches the target.
Drop off and Seoul will take the ball — and they take fewer points in those matches. But note that their xG goes up in them, not down.

If you are Seoul

What is left when the conversion comes back? Regressed to the league average, the goal difference goes from +28 to +8. This lead was not built by creating more.
Eighteen per cent through the middle. 82% of final-third entries are wide, and the crosses at the end of them turn into a shot once in five. More central entries would raise the xG itself.
Two goals from 129 corners. The league's second-highest supply, almost unconverted — the cheapest improvement available. (Hwaseong, in part 1, had the same problem.)
Ku Sungyun has played every minute of all 25. No alternative exists in the data.

Appendix — data, verification, limits

Source and scope

Everything comes from the Korea Professional Football League's K League Data Portal (data.kleague.com), public data. Collected 2026-08-29, covering the 25 matches Seoul played through round 25 of K League 1 2026; every league comparison uses the 12-club snapshot from the same moment. ⚠ As of 4 September the table has Seoul on 26 matches and 56 points, so this piece sits one match behind. Updating one club alone would break the league comparison, so the snapshot was kept whole.

Cross-checks

League table vs the sum of match results: exact match (25 games, 16-5-4, 53 points, 47-19)
Opponent goals in the event feed vs official goals against: exact match (19)
Opponents' shots on target — 82 in the supplementary records against 83 in the event feed: one apart
Seoul goals — 44 in the event feed against 47 official: three apart, own goals and tagging gaps. The match record is the authority for goals; the event feed is used only for spatial, time-band and xG work.
Coordinate normalisation: mean shot origin at X 86.9 for Seoul and 85.1 for opponents — both correct

⚠ The same metric name means different things in different places

Seoul's season shot count is 299 in the supplementary records, 276 in the official records and 295 in the event feed — three different numbers. Shots on target is 108, 148 and 104. xG splits too: 36.86 on the portal's official model, 37.64 summed from events. The portal runs several counting systems, and none of them is wrong; they are defined differently. This piece uses the supplementary records for all 12-club comparisons, the event feed for coordinates, time bands and per-match xG, and the portal's official value for team-level xG, and never mixes them. The 43.5% conversion is on the supplementary system (47 goals ÷ 108 on target), with all twelve clubs computed the same way.

My own definitions (not official metrics)

Conversion — season goals ÷ season shots on target. Penalties and own goals sit in the numerator, so it is not a pure open-play finishing figure. Seoul have one of each, so the effect is small.
Possession phase — one side's spell until the opponent registers two consecutive events
Final-third entry — a pass starting below X 66.7 and ending at or beyond it; the channel is the outer or middle third of the ending Y
Mean defensive-action position — the starting X of tackles, interceptions, blocks, recoveries and clearances, rotated to attacking direction and averaged
Box-entry phases and cross outcomes — derived by me from the event feed. The window for judging "a cross became a shot" (within the same possession phase) is my own choice.

What this piece does not answer

Whether the conversion is skill or variance. Twenty-five matches cannot settle it; the remaining rounds will.
What changes between the 46th and 60th minute. Substitutions, instruction or opponent fatigue — the data does not separate them.
Whether 18% central entry is a design or a consequence. Opponents sealing the middle and Seoul choosing the flanks look the same in an event feed.
The goalkeeper's contribution could not be isolated. The portal carries no post-shot xG.
What produces the league-leading fouls-won figure. The way they hold the ball, individual ability, or the refereeing environment.

All of them need video, inside information, or a longer sample. Marking where the data stops is the rule of this series.

Two companion reports

Two other pieces go deeper into single phases of the same dataset. "Everyone gets the ball to the same place" sets Seoul's deliveries into the central zone in front of goal against their opponents'. "How the league learned to play FC Seoul" follows how 11 opponents changed their block for the return fixture. If this piece is the outline of the team, those two magnify one section of it.