Liverpool v Tottenham Hotspur - Barclays Premier League

Resident hockey expert Justin Bourne wrote a stellar piece on “score effects” in hockey this morning. Here is a good definition of score effects via the popular Toronto Maple Leafs blog, Pension Plan Puppets:

Teams that are behind tend to get more shots and scoring chances because they press to get back into the game, and often the team with the lead naturally sits back and absorbs pressure. Conversely when the game is tied, or close (within a goal, or within 2 in the 3rd period) teams tend to play a much more balanced approach, giving up as little as possible, and working to score more goals on offense.

Interestingly, this effect persists in soccer too where it’s generally referred to as ‘game states’.

Bourne offers up a few theories for the root cause of this effect in hockey. One in particular however stood out for me: simple psychology. When their team has a lead, coaches tend to put out less talented players and their more talented players are under greater pressure to avoid mistakes:

What they do want, is Jay McClement to chip the puck out of the zone because, like fans, they’re less stressed when the puck isn’t in their zone. So, it gets out, coach feels relief, sees who made the clear, and the rat has been rewarded. He wants more of that.

If we were a behavioral psychologist, we might refer to the psychological response to the scoreline as a kind of heuristic. To borrow the Wiki definition:

In psychology, heuristics are simple, efficient rules, learned or hard-coded by evolutionary processes, that have been proposed to explain how people make decisions, come to judgments, and solve problems typically when facing complex problems or incomplete information.

Now I’m bending the rules a bit here, but in soccer, game states are a persistent effect, to the point where there is clearly something going on which goes beyond conscious tactical adjustment. I haven’t conducted a study but I’m inclined to think the persistence of score effects/game states underscores a fairly natural team response to a lopsided scoreline.

Anyone who’s ever played a team sport knows it. You’re losing, your team gets desperate, you all push up the pitch to try to get back in the game, and in doing so you leave yourself open at the back. You see it in football matches all the time.

Now in behavioral psych, heuristics become interesting when they lead to cognitive biases: decisions that feel right but are in fact ‘illogical’ (not to sound too much like Spock). If you’re aware of this pitfall, you can use it to your advantage either by avoiding it yourself or taking advantage of it in others.

And this where we get to Brendan Rodgers’ 2013-14 Liverpool FC.

They are league leaders on 71 points and the talk of the league, playing a breathtaking, attacking style of football that puts asses in the seats. Great stuff for the neutral.

Some, like Michael Cox on yesterday’s Guardian Football Weekly podcast, point to Liverpool’s incredible counterattacking ability. That view fits with some telling statistics courtesy of the great and vital work of Ben Pugsley.

First, a primer on some advanced stats in soccer.

Liverpool are third overall in the Premier League behind Man City and Arsenal in TSR at a tied Game State, but are eighth in TSR Close (which included tied and +1 Game States). Moreover, Liverpool shoot once per 11 passes, the second smallest ratio in the league (they’re behind Newcastle).

From this we can glean a few possibilities. At a tied game state, Liverpool are effectively dominant, outshooting their opponents and pushing for an opening goal. However, we can safely assume that Liverpool are spending a good amount of time at +1, which is when the losing side tends to push up the pitch and take more shots, opening up space behind them which a quick attacking force of the likes of Sterling, Sturridge and Suarez can take ruthless advantage. The speed of Liverpool’s transition to attack could also be reflected in their very low passes-to-shots ratio.

Now you don’t need statistics to tell you the advantages of working hard to score the first goal, then sitting back to play aggressively and quickly on the break. But Liverpool’s approach also neatly fits with a statistically consistent, apparently universal predictable pattern of play observed in Game States.

It’s also clear that many top tier teams don’t adjust their play to take advantage of the Game State effect, for example relying on plodding build up play allowing the opposition defense to track back in time to defend in numbers.

Now I don’t know what kind of data LFC and Rodgers tracks, but here is a clear area where a coach can take a statistically measurable effect like the Game State heuristic, and use it to their advantage. See? Analytics in action, and you may not have even realized it.