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Thursday, 28 May 2015

Goalkeepers Are Voodoo: The 2014/15 Edition

Right, before we get stuck in, a key:

- Save% = 100-goals against/shots on target against
- GSAA (Goals Saved Above Average) =  SoT Against * League Average Scoring% - Actual Goals Against
- GSAA p90

Goals Saved Above Average sounds like a tricky little thing to calculate or understand but it's actually quite simple: how many goals did Goalkeeper X prevent above/below replacement level. If we convert that metric into a per90 we get a decent rate stat. Small samples always skew evaluations so make sure to check the number of games each goalkeeper played in.

Poor Rob Green shipped the most goals against and faced the most shots on target against.

Best full-time save%? David Ospina with 81% in 18 games. That 81% number is almost 5 percentage points higher than anyone else in the league. Does anyone believe David Ospina is that good? ....
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Thought not.

Costel Pantillimon is yet another Sunderland goalkeeper to lead the league in this stat. Weird things going on at Sunderland with goalkeepers (probably deep set D, good midfield block due to an inability to keep the fucking ball, win the territory battle etc..)

David Ospina shows up again leading the league in Goals Saved Above Average p90 for full-time players.

Goalkeepers are voodoo, we struggle to evaluate them. Guys we think are good may indeed be actually good in that given season, but we have no true and trustworthy way of saying how good they will be next year.

Search for Brad Jones.....please.


Team Full Player Name Age Games Goals Against SoT Against Saves Save% GSAA GSAA p/90
Sunderland Costel Pantilimon 28 28 33 142 109 76.8 10.7 0.4
Swansea Lukasz Fabianski 30 37 46 182 137 74.7 10 0.3
Arsenal David Ospina 26 18 11 58 47 81 6.8 0.4
West Ham Adrián 28 38 47 174 129 73 6.5 0.2
Southampton Fraser Forster 27 30 21 82 61 74.4 4.2 0.1
Chelsea Petr Cech 33 6 2 18 16 88.9 3.5 0.6
Man Utd David De Gea 24 37 36 128 93 71.9 3.4 0.1
Man City Joe Hart 28 36 34 119 87 71.4 2.6 0.1
Hull Steve Harper 40 10 10 40 30 75 2.3 0.2
Burnley Tom Heaton 29 38 53 179 128 70.4 2.1 0.1
Chelsea Thibaut Courtois 23 32 30 103 74 70.9 1.7 0.1
Stoke Jack Butland 32 3 2 12 10 83.3 1.7 0.6
Man Utd Victor Valdés 33 1 1 7 6 85.7 1.2 1.2
Leicester Ben Hamer 27 8 8 29 21 72.4 0.9 0.1
West Brom Ben Foster 32 28 34 109 75 68.8 0.5
Everton Joel Robles 24 6 6 21 15 71.4 0.5 0.1
Leicester Mark Schwarzer 42 6 10 33 23 69.7 0.2
Newcastle Robert Elliot 29 3 2 7 5 71.4 0.2 0.1
Hull Eldin Jakupovic 30 2 2 7 5 71.4 0.2 0.1
Aston Villa Jed Steer 22 1 1 3 2 66.7 -0.1 -0.1
Leicester Mark Schwarzer 42 6 10 32 23 68.8 -0.2
Palace Wayne Hennessey 28 2 2 6 4 66.7 -0.2 -0.1
Tottenham Michel Vorm 31 3 5 15 10 66.7 -0.4 -0.1
Tottenham Hugo Lloris 28 35 48 154 107 68.8 -0.6
Southampton Paulo Gazzaniga 23 2 3 7 4 57.1 -0.8 -0.4
Arsenal Wojciech Szczesny 25 17 21 65 45 67.7 -1 -0.1
Man City Wilfredo Caballero 33 2 4 9 6 55.6 -1.2 -0.6
Swansea Gerhard Tremmel 36 1 3 5 2 40 -1.5 -1.5
Arsenal Emiliano Martinez 22 3 4 7 3 42.9 -1.8 -0.6
Leicester Kasper Schmeichel 28 24 37 113 80 67.3 -2.2 -0.1
Liverpool Simon Mignolet 27 35 43 132 89 67.4 -2.4 -0.1
Aston Villa Brad Guzan 30 34 48 148 101 67.6 -2.5 -0.1
Liverpool Brad Jones 33 3 5 8 4 37.5 -2.5 -0.8
Southampton Kelvin Davis 38 6 9 20 11 55 -2.8 -0.5
Aston Villa Shay Given 39 3 8 17 9 52.9 -2.8 -0.9
Stoke Asmir Begovic 27 35 43 129 86 66.7 -3.3 -0.1
QPR Alex McCarthy 25 2 8 13 5 38.5 -4 -2
Sunderland Vito Mannone 27 10 20 51 35 60.8 -4.3 -0.4
QPR Robert Green 35 36 65 194 132 66.5 -5.3 -0.1
Palace Julian Speroni 36 36 49 139 90 64.7 -6.2 -0.2
Newcastle Tim Krul 27 30 47 129 83 63.6 -7.3 -0.2
Hull Allan McGregor 33 26 39 103 64 62.1 -7.3 -0.3
Everton Tim Howard 36 32 44 107 65 58.9 -11.1 -0.3
West Brom Boaz Myhill 32 10 34 71 75 52.1 -12.2 -1.2
Average 30.2 17.3 22.5 72.6 50.1 69.1 0.0 0.0
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