Words of caution: goalkeeper rotation

Each year the home/away fixtures for Premier League clubs are scheduled to rotate perfectly with those from one other club. Enterprising fantasy managers often attempt to take advantage of this policy by seeking out favourable rotation pairings and planning their squad so that they will have a goalkeeper playing at home each gameweek. (See Aaron’s post for a list of the 2013-2014 rotation pairings).

Inevitably, rotations fall by the wayside as injuries occur or form dictates a change. Sometimes this happens within the first few weeks of the season, but some lucky few stick with their keeper rotation all the way to the January wildcard.

Regardless, goalkeeper rotation is a big topic of conversation prior to every FPL season. Which rotation pairings will offer the most points? Which ones give the best value options? Is it even worth spending the extra money on a second starting keeper?

It’s this last question that I intend to answer here. As outlined in my previous piece, goalkeepers don’t provide a large differential compared with the other positions, and keepers from top 5 clubs do not reach their expected value. For these reasons, it would be essential for the benefits of keeper rotation to dramatically outweigh the increased cost associated with the inclusion of two starting keepers in your squad.

We can explore this dilemma using the data from the 2012-2013 season. As shown in the table below, the number of points you would have received by rotating keepers was usually somewhere in between the number of points you would have received by choosing one of the two and sticking with that one throughout the entire season.

Team with higher scoring keepers Team with lower scoring keepers High team points Low team points Points if rotated
Liverpool Everton 149 129 157
Sunderland Newcastle 140 110 145
Man City Man Utd 158 140 158
West Ham Stoke City 144 144 141
West Brom Aston Villa 130 110 125
Chelsea QPR 150 120 144
Swansea Reading 143 119 133
Norwich Wigan 133 96 118
Arsenal Tottenham 146 119 125

So rotation lowers the risk of choosing a keeper from the wrong team. This makes sense, as the idea behind keeper rotation is analogous to the diversity portfolio concept in financial management. More assets results in less risk.

That being said, the safety of goalkeeper rotation didn’t outweigh the benefits of sticking with one keeper last year. When compared to the higher-scoring of the rotation pairs, the keeper rotation strategy only scored more points in 2 of the 9 instances (Liverpool/Everton and Sunderland/Newcastle, as shown in the table below).

Team with higher scoring keepers Team with lower scoring keepers Point benefit by rotating keepers Additional cost of rotating keepers
Liverpool Everton +8 1.5
Sunderland Newcastle +5 1.5
Man City Man Utd 0 2.0
West Ham Stoke City -3 0.5
West Brom Aston Villa -5 1.0
Chelsea QPR -6 0.5
Swansea Reading -10 0.5
Norwich Wigan -15 1.0
Arsenal Tottenham -21 1.5

So despite having to pay more for two starting goalkeepers (rather than picking one starting keeper and a 4.0 back-up), you are far less likely to come out ahead by rotating keepers than if you simply make the correct decision on one and stick with him.

The bottom line: tread carefully when deciding whether to rotate your keepers. Consider whether the added cost outweighs the benefits of rotation, particularly when that 1.5 or 2 million might be better spent upgrading a midfielder or forward.

Last year’s data suggests that the goalkeeper rotation is a foolhardy policy, but who knows what this season will bring!