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Monday 5 March 2012

Why Abramovich Sacked Villas-Boas.

Expectation is everything in football and fans and owners often share a common trait of impatience and recency bias.The impatience arises when the manager and the team fails to deliver in a timely manner the proper level of success commensurate with the level of support provided.Be it financial in the the case of the owner or financial and vocal in the case of the supporters.This slightly unfair bargain often ignores the many uncontrollable factors that make the difference between winning or losing a game of football.Injuries and luck being two such factors.

Recency bias can cut both ways for a manager,as a recent good run can elevate him to the heady heights of hero status,while a run of winless matches can quickly see the terraces and boardroom calling for his head.A prime example of this is the current situation at Stoke where the team currently have their best post February points total,are FA Cup Quarter finalists again,have enjoyed 3 and a half years of Premiership football and have played 44 matches so far including a run to the knockout stages of the Europa Cup.For a club of Stoke's limited resources this is success beyond most people's expectations.Yet despite this enviably record there is a minority of fans who are calling for a change at the top.A run of consecutive losses is the usual catalyst for the unrest.Follow that up with complaints about team selection and a disagreement about prioritising the Premiership over the Europa adventure and you soon have a manager under siege.Although fortunately for Stoke,their owners are made of stronger and more sensible stuff.

Pulis' near neighbour,Harry Rednapp at Tottenham has also just this weekend discovered that third place in the Premiership offers no protection in the face of back to back high profile losses to fellow high flyers,especially if fan's favourites are left on the bench.

Fans are fickle and there's no reason to suppose that owners are much different

One man who failed to survive a dip in expectations was of course Andre Villas-Boas at Chelsea,who experienced the same fate as befell his double winning predecessor,Carlo Ancelotti.The bar is set much higher at Chelsea than at most other clubs,but the same factors that conspire to make all managers vulnerable exist at Stamford Bridge.

Owner,player and manager relationships play some part in how partnerships fracture,but reliable information on these factors will never make the public domain,but we can quantify the publicly displayed interactions between the manger and his players.Fan satisfaction with the manager on match day can be broken down into three easily digestible pieces.Firstly,what was the starting eleven and how did they perform? Next,did his substitutions help the team to the best possible result and lastly,what was the final score and did the result come close to meeting expectations.

To quantify these three factors I've used my Expected Points model to look at every Chelsea EPL game from Ancelotti's last season in charge of Chelsea and all 27 of AVB's EPL games before he was axed after defeat to WBA on Saturday.

Chelsea "Heat Map" Under Ancelotti 2010/11 EPL Season.

Opponent.
Time
of 1st Sub.
Time
of 2nd Sub.
Time
of 3rd Sub.
EP
@ Start.
EP
@ 1st Sub.
EP
@ 2nd Sub.
EP
@ 3rd Sub.
Final
Points.
WBA
60
65
70
2.65
3.00
3.00
3.00
3
@Wigan
63
70
79
2.56
3.00
3.00
3.00
3
Stoke
72
81
85
2.75
2.95
3.00
3.00
3
@WHU
76
82
83
2.46
2.99
2.99
3.00
3
Blackpool
72
75
78
2.75
3.00
3.00
3.00
3
@ManC
69
75
81
1.65
0.44
0.36
0.28
0
Arsenal
73
83
89
1.99
2.69
2.77
2.99
3
@Villa
45
76
76
1.99
1.78
1.49
1.49
1
Wolves
72
79
82
2.75
2.94
3.00
3.00
3
@Blackburn
72
89
-
2.24
1.68
2.89
-
3
@Liverpool
45
70
76
1.72
0.24
0.10
0.07
0
Fulham
78
85
89
2.73
2.95
2.96
2.97
3
Sunderland
58
69
75
2.56
0.50
0.30
0.21
0
@Birmingham
65
72
-
1.99
0.62
0.52
-
0
@Newcastle
80
-
-
1.99
1.43
-
-
1
Everton
65
78
88
2.40
2.80
2.84
1.37
1
@Spurs
45
68
78
1.44
0.54
0.37
1.23
1
@Arsenal
45
56
61
1.33
0.49
0.02
0.08
0
Bolton
89
89
-
2.46
2.92
2.92
-
3
Villa
57
73
79
2.53
1.03
0.68
0.53
1
@Wolves
66
72
79
2.24
0.76
0.64
0.48
0
Blackburn
80
80
87
2.50
2.99
2.99
3.00
3
@Bolton
72
77
-
2.06
3.00
3.00
-
3
@Sunderland
77
82
89
2.06
2.75
2.79
2.87
3
Liverpool
75
84
-
2.06
0.48
0.28
-
0
@Fulham
66
71
-
1.95
1.59
1.54
-
1
ManU
61
71
81
1.65
1.45
1.38
2.68
3
@Blackpool
55
72
75
2.50
2.83
3.00
3.00
3
ManC
70
71
77
2.06
1.60
1.59
1.50
3
@Stoke
61
61
80
2.05
1.70
1.70
1.45
1
Wigan
45
59
75
2.55
2.25
2.09
2.87
3
@WBA
63
77
82
1.99
2.94
2.97
2.98
3
Birmingham
57
67
68
2.68
2.99
3.00
3.00
3
WHU
57
70
77
2.68
2.91
2.91
2.92
3
Spurs
57
63
73
2.29
1.91
1.84
1.69
3
@ManU
45
45
62
1.29
0.12
0.12
0.08
0
Newcastle
64
64
64
2.59
2.05
2.05
2.05
1
@Everton
61
70
78
1.51
1.36
1.32
0.29
0

At every point in a match a team will have a probability of winning the match and a probability of drawing.These probabilities will depend on the relative merits of both sides,the current score,time remaining and less common outcomes such as red cards.This allows us to calculate how many league points a team should gain on average for any point from the first whistle in August to the last one in May.It also allows us to see how the manager's starting 11 fare each week and how able a manager is to  improve the fate of his team by the introduction of substitutes.By seeing if a team's Expected Points rose or fell with every managerial decision we can gauge how pleased both the fans and more importantly the owner would have been with their coaches actions.

In the table above and below I've labelled a rise in EP in blue and a fall in red and the numbers relate to the performance of the starting 11,followed by that of the team with first one,then two,then three substitutes.

To demonstrate look at AVB's second game in charge below at home to WBA.At kickoff Chelsea would expect to get an average of 2.5 points from such games,by the time of the first substitution,WBA led 1-0 and the Blues' EP had fallen to 1.42.Therefore,the red number 1.42 indicates that the starting 11 under performed.

During the time Chelsea were playing with just one substitute,Anelka equalises via a deflection in the 53rd minute and when the second substitute appears after 60 minutes their EP has risen from 1.42 points to 2.02 points.Thus the blue 2.02 figure indicates that the first substitution has had a positive impact on the team's EP and presumably the fans are happy with AVB's course of action.

Chelsea play with two subs for just six minutes from the 60th minute to the 66th,but no more goals are scored and the clock has ticked nearer to full time and their EP has started to track towards one point for the draw.So a negative period of play for the two sub combination denoted by the red 1.93 in the three subs column,albeit only slightly.The final sub appears after 66 minutes and Chelsea grab the winner about 20 minutes later.The three sub combination is highly productive raising the Expected Points from 1.93 points after 66 minutes to the (blue) 3 points at full time.AVB is a tactical genius and everyone is happy,although 2 of the four playing periods were negative and things could have ended differently.

Chelsea "Heat Map" under Andre Villas-Boas 2011/12 EPL Season.

Opponent.
Time
of 1st Sub.
Time
of 2nd Sub.
Time
of 3rd Sub.
EP
@ Start.
EP
@ 1st Sub.
EP
@ 2nd Sub.
EP
@ 3rd Sub.
Final
Points.
@Stoke
66
76
89
1.99
1.61
1.49
1.23
1
WBA
35
60
66
2.50
1.42
2.02
1.93
3
Norwich
68
71
83
2.62
2.00
1.94
2.96
3
@Sunderland
62
74
79
1.99
2.94
2.96
2.97
3
@ManU
45
68
79
0.96
0.07
0.04
0.02
0
Swansea
60
79
83
2.62
2.91
3.00
3.00
3
@Bolton
54
56
73
2.17
2.99
2.99
3.00
3
Everton
65
77
77
2.40
3.00
3.00
3.00
3
@QPR
36
47
72
2.40
0.65
0.49
0.27
0
Arsenal
62
72
76
2.06
0.69
0.53
0.46
0
@Blackburn
45
83
89
2.29
2.02
2.83
2.89
3
Liverpool
45
84
84
1.92
0.84
1.33
1.33
1
Wolves
70
77
78
2.59
3.00
3.00
3.00
3
@Newcastle
61
75
79
1.65
2.50
2.61
2.65
3
ManC
73
84
88
1.51
1.76
2.90
2.92
3
@Wigan
45
66
80
2.39
2.12
2.80
2.84
1
@Spurs
33
48
78
1.36
1.33
1.31
1.20
1
Fulham
62
71
81
2.48
1.98
1.83
1.60
1
Villa
57
63
75
2.50
2.06
1.98
1.76
0
@Wolves
84
-
-
2.11
2.80
-
-
3
Sunderland
73
85
-
2.33
2.80
2.87
-
3
@Norwich
37
77
79
2.11
1.93
1.53
1.50
1
@Swansea
65
80
-
1.75
0.53
0.32
-
1
ManU
71
-
-
1.47
2.51
-
-
1
@Everton
69
77
78
1.59
0.41
0.05
0.04
0
Bolton
76
80
88
2.47
2.99
3.00
3.00
3
@WBA
64
76
84
1.81
1.52
1.41
0.26
0


The amount by which the Expected Points value change are of course important,but we can get a feel for how both Ancelotti's and Villas-Boas' team selections and tactical substitution were likely to have been received both on the ground and in the luxury boxes by looking at the percentage and grouping of the negative decisions.The red areas of the tables are times in a match and during the season when both managers were probably feeling the heat both from fans and from Abramovich.Hence I've called them "Heat Maps".

Red figures in the final columns are particularly bad news for top teams such as Chelsea,because they also  represent a real average loss of league points over fan and owner expectation,but intra match red numbers can also make the boss appear powerless to influence on field events while the contest is in progress.

Overall in 2010/11 Ancelotti had 68 positive and 76 negative passages of team play and 16 out of 38 occasions when the actual final points haul fell below that expected from pre game estimates.So he hovered around a 50% success rate under this analysis and did extremely poorly over the last four games prior to his sacking immediately after the loss to Everton.Villas-Boas exceeded those figures,scoring a 52% failure rate in both categories and also performed very poorly in both areas over the last six games of his reign.

In doing so he obviously exceeded Abramovich's tolerance threshold as well.

2 comments:

  1. Brilliant analysis, well written and extremely interesting. Was wondering if you could do a post about Liverpool's signings over the 2 years and how much statistics impacted the decision to sign the players. (Downing and Henderson's high "chances created" stats) Why didn't this strategy (which brought the Red Socks, of the same owner, glory) did not work.

    ReplyDelete
  2. Cheers,Max.
    Nice idea about Liverpool.I'll put something together in the near future :-)

    ReplyDelete