How Passing Sequences Create Chances.

In previous posts we've looked at individual passing attempts and how the pitch position of both the passer and the intended receiver impacts on the difficulty of the pass and therefore the likelihood that the pass will be successfully completed. However, the true worth of a team's passing prowess only really becomes apparent when these individual passes are reconstructed into their original passing sequences. 

All of the data that has been used to construct these passing expectancies has been taken from the Bolton Manchester City game from the Reebok, so the usual caveats apply. The conclusions may not be entirely representative of the wider Premiership, although the contrasting styles of each team may reduce this potential problem and the relative closeness of the scoreline throughout the game probably means that both teams had a relatively attacking outlook throughout.

Below I've merely listed the the number of passing moves in each passing sequence before the passing chain is terminated through loss of possession via such events as a shot, a foul, a misplaced pass or a tackle. Every pass is intended to be completed, so I've included "chains" comprising of one misplaced or uncompleted pass and I've also initially terminated chains were a player successfully beats an opponent in a "take on" situation.

Both Bolton and Manchester City attempted very similar number of passing sequences. This is virtually inevitable because a new sequence will tend to start once possession is lost by the opponent and by including single pass chains we can get a clearer picture of the use each side made of it's possession. 

The differing passing styles on that particular match day is clearly visible in the figures. Both teams were equally careless when conceding the ball with their first attempted pass, but the visitors had more longer passing chains than Bolton. City produced nine passing sequences that lasted into double figures compared to just two for the hosts. Equally striking is the concentration of passing sequences for both teams that terminate after just a handful of passes, upwards of 84% of passing moves lasted for four passes or less

Lengths of Passing Chains from The Bolton v Manchester City Game.

No. Of Passes In The Chain.	Manchester City.	Bolton Wanderers.
1	100	93
2	24	46
3	16	15
4	17	10
5	7	5
6	7	2
7	4	4
8	4	0
9	2	5
10	3	0
11	1	0
12	1	0
13	0	0
14	0	1
15	1	0
16	1	0
17	1	0
18	1	1
Total.	190	182

Much of the previous detail could probably have been guessed at without looking at the actual data. Manchester City are an expensively assembled side who have quality players throughout with the ability to   play a possession based style, while Bolton are traditionally a much more direct team who have recognized the profit to be reaped from delivering the ball rapidly into dangerous areas of the pitch. 

It's only when we begin to look at the combined difficulty of each pass that goes to make up each chain, the input from individual players and the likelihood of chains of differing lengths and from differing starting points producing an attempt on goal can we begin to place passing as a skill into a game context.

We've seen that most passes attempted in a match have an extremely high likelihood of being completed, with the difficulty increasing, predictable with increasing pass length and in areas in and around the opponents goal. 

If we use as an example, Bolton's longest passing sequence which was started by Chris Eagles, midway inside his own half in the 50th minute, comprised 18 completed passes before the same player dragged a chance wide of City's right hand post. Over half of the 18 passes had completion expectations in excess of 80%, the most difficult pass was attempted by full back Robinson on the 12th pass of the move (58% completion expectation), and Eagles contributed six passes to the move in addition to producing the goal attempt. Based on the data and the individual pass expectations, Bolton had about a 1% chance of completing such a move and the last four passes were among the sequence's most difficult attempts. Eagles had around a 10% chance of scoring with his effort. Once we put all these numbers together it quickly becomes apparent why football is a low scoring sport!

This method allows us to pick out not only players who allow longer passing interplay to continue, but also those who may be playing the more difficult passes. Silva and Toure were frequently the most involved players in such Manchester City moves and Silva also linked together small passing sequences with successful "take ons" of opponents. Barry and Milner shared the honours for attempting the most difficult passes of these extended interchanges.

However, given the apparent difficulty in prolonging passing movements and the cash outlay required in player recruitment to build a team capable of producing such sequences, what is the payoff in chance creation? Again sample size is a big caveat, but two factors appear important when turning passing plays into goal attempts. These are, again logically, the area on the pitch where the move originates and the number of completed passes.

Below I've charted how likely it is that a chance will arise from varying lengths of passing sequences, originating from different pitch areas. Winning possession in the final third appears as significant a factor as passing ability. Based on the MCFC data, three passes originating in the final third is likely to produce a goal attempt 10% of the time. To have a similar likelihood of threatening the goal from your own penalty area over four times the number of uninterrupted completions are required. Predictably the combination of last 3rd possession and potent, prolonged passing ability gives a team a better than even money chance of a scoring opportunity arising.

Pass Sequence & Field Position & Their influence On Chance Creation.

Starting Area For Sequence.	Number Of Passes.	Chances of Producing A Goal Attempt.
Edge Of Own Box	13	10%
Edge Of Own Box.	3	0.5%
Last 3rd.	13	65%
Last 3rd.	3	10%

By pooling such factors as passing sequence, final 3rd possession and the ability to take on and beat opponents we can highlight where and why scoring opportunities arise, prioritize attainable recruitment of new players and formulate tactics that play to a team's strength and ability.

Swansea make a rare passing excursion into the final third.

We can also add context to such pass orientated teams as Swansea, who invariably begin their sequences deep in their own territory and therefore probably require much longer sequences to create comparable chances, especially with their exaggerated tendency to pass sideways or backwards. On Saturday, the Swans out passed and out possessed Stoke, but were out shot and comfortably beaten on the scoreboard.