K League Coach: A Study of K League vs Premier League Part 2

The K League Coach returns with a study of goals and the actions leading up to goals between the English Premier League and the K League 1. The analysis of the goals will be broken down into three areas, the finish, the assist and the transitional moment. This will highlight similarities and differences in style of play between the leagues. Part two of the K League Coach's "What are we Watching?" series looks at where the assists come from.

Introduction

In a comparison of K League and the English Premier League, particular focus will be applied to the actions involved in 'open play',goals and the actions leading up to them. Definitions of terminology will be put forward in each section as it becomes relevant.

The goals analysed will come from a similar time frame, the initial seven rounds of the K League 1 season between March 1st 2019 and April 14th 2019, and and six rounds of the English Premier League (EPL) season from February 22nd to March 31st. The additional round of games for the K League was due to there only being six games per week, compared to 10 in most weeks in the EPL. It brought the number of games per league closer while still being in a similar time frame During this period there were 53 EPL games over six rounds of play, resulting in 150 goals, and 42 K League 1 games over seven rounds resulting in 95 goals

Part 2 - Assist Actions

To better understand each league's style of play, a step back from the goal must be taken, and an analysis of each goal assist should take place. An assist will be defined as “the previous touch by a team mate directly preceding the goal scorer receiving the ball”. This means there must be at least a chain of one successful pass for there to be an assist. No assist will be given to penalties or direct free kicks and we will not include direct free kicks, corner kicks, set pieces into the final third, own goals, or deflected fluke goals. As with part one, only goals from open play will be analysed. “Open play” will be defined as moments when teams are playing in their flow, within their own formation.  “Set piece” will be defined as restart moments such as corners, throw-ins, penalties, direct free-kicks, or set pieces delivered into the final third. These set piece moments distort the numbers of players in certain areas and require distinctly different behaviour. So any goal that originates from one of these moments with teams in an “set piece” shape will not be included regardless of there being a flicks-on, layoffs or rebound.

• The EPL had 150 goals in the set period, 99 came from open play and 94 of those goals had an assist (94.95%).
• The K League had 95 goals in the set period, 71 came from open play and 61 of those goals had an assist (85.92%).

This difference in assist percentage suggest more K League goals came from defensive errors such as turnovers or rebounds, or moments of open play that have no assisting player.

2.1 Assist Location

Assist location was recorded using the map below. These areas reflect commonly used zones within football, such as the central channel (4&9), the inner channels (3&8 & 5&10) and the flanks (2&7 & 6&11). These channels are then split across the top of the penalty box. 

Assist Locations

EPL Assist Locations

K League Assist Locations

As shown in the two diagrams above, direct assists from deep provide a similar percentage of assists across the two leagues (18.09% in the EPL and 19.67% in the K League). Another similarity can be seen in the success teams have in scoring with assists coming from zones 8 and 10. In the EPL these two zones accounted for 32.78% of assists, and 34.6% in the K League. The inner channel areas within 18 yards from goal can be seen as “golden zone” for assists. A third similarity between the two leagues assist locations is the low return from the wide channels. The four zones in the wide channels provided 6.56% of K League assists and 6.39% in the EPL.

The one area of difference across the two leagues is the percentage of assists coming from the central channel. Though combined zone 4 and 9 provided around 38% of assists, similar to that of the “golden zone”, the assists from the individual zones are flipped. The K League had more central assists coming from the edge of the box, whereas in the EPL central assists came from within the penalty box.

2.3 Assisting Pass Type

Once in the high assist return areas it is important to analyse what type of assist was provided. Each assist will be assigned to one of three categories:

Ground Pass: The ball came to the goal scorer having never been higher than his knee. 

Body Height Pass: The pass to the goal scorer at some point went above their knee, but remained below the player's head height for the entirety. Such types of assist may be balls whipped into the striker off the ground, but not going over a defender or the striker's head at any point. The finish did not require the scorer to leap off the ground.

Above Head Height Pass: Though the ball may have arrived at the goal scorer at any height, the ball was delivered in a manner that it went over their head height, or a defender's head height at some point. This can be a cross into the box finished with a header, or a long highball that arrived at the strikers feet.

Assist Types

It is clear from the graph above how important delivering the ball on the ground is to scoring goals. Even combining assist from Body Height Passes (BHP) and Above Head Passes (AHP), together they do not provide half as many assists as passes along the ground. This suggests that such deliveries provide the next player with an easier finishing opportunity, but also a tactical decision by teams to actively focus their attacking around creating chances on the ground.

Conclusions

• Both the K League and the EPL see a large percentage of their assists coming from the inner channels with 18 yards from goal. 
• Zone 8 & 10 show a consistent rate of return across both leagues.
• Traditional wing play seems to have less of an impact or use in both leagues' style of play.
• Knowing what locations on the field return the most goals, it seems getting closer to these areas before attempting an assist will give teams a better chance of scoring.
• Short passes across the ground from the assisting player are the most popular form of assist.
• The inner channel offering a better rate of assists than the other channels may be to do with how the positioning of the goalkeeper is effected. When out wide a goalkeeper can remain central, but as teams enter the inner channel the goalkeeper must move across to protect the near post, leaving the far side open.

K League Coach Considerations

• Zone 4 saw an almost 7% increase in assists in the K League, are teams failing to protect this area properly?
• The decrease in assists directly in front of goal may suggest that teams are not getting the numbers into the box when attacking so that players may combine.
• Across the K League 64.21% of goals come in open play with an assist, 10.53% come from open play with no assist, and 25.26% come from set pieces. 
• Some interesting outliers are Daegu, Gangwon and Ulsan, who currently have 100% of their goals coming from open play and assisted. These teams may need to look at how they may make more of set piece scenarios or force more opposition errors to improve their goal scoring.
• Interestingly, at the time of this analysis Ulsan sit top of the table. They have scored 11 goals across seven games so far. Only 45%  of these goals have come from open play with an assist. This suggest that they may be more reliant on set pieces and opposition errors for unassisted open play goals.