Forrest for the Trees

Article by James Dailey (@jucojames)

Perhaps no Celtic player has been a better case study for human cognition than James Forrest. People often formulate impressions and opinions of players early in their tenure with the club, which creates a cognitive anchor of sorts. We homo sapiens all think we are rational, but our minds play tricks on us, as we’ve evolved with survival at the forefront rather than rationality. For example, the statistical probability of that rustling behind you in the forest being a bear or lion is very low, but our brains are engineered to flee just in case. Or, given the choice of being given a certain £1,000 vs a 50% gamble at a £5,000 payout, why do a vast majority of people take the certain £1,000? The rational thing to do is to calculate the statistical expected value and then take the higher amount: 0.50/5,000= £2,500.

I believe James Forrest has two very important cognitive anchors in the minds of many in our support. First, he has been at the club for so long that many developed opinions and impressions early in his tenure, when he was more injury prone and inconsistent. The resulting confirmation bias unfolds when he has a poor game and people “feel” those games more. Second, many in the Celtic support mentally weight performances against Rangers more heavily than other games.

I will not get into statistical definitions other than to say that Standard Deviation is one basic statistical measure to assess absolute levels of variability – basically a lower figure suggests more consistency. I’ve normalized Expected Goals (xG) and Expected Assists (xA) to be per 90 minutes:

Generally speaking, Forrest’s performance levels, as measured by xG and xA per 90 minutes of play, have been less volatile than the performance levels of Scott Sinclair during his incredible 2016/2017 season, and comparable to Patrick Roberts’ most productive stint at Celtic the same season.

Are we all “wrong” for believing that Forrest is inconsistent? I would say probably “yes”, but it is completely understandable. Forrest has been significantly less effective against Rangers and in a consistent way. Recency bias is the normal human tendency to place a greater mental weight on more recent events, and Forrest has produced literally zero xG and xA in the three games versus Rangers this season. In addition, he’s produced zero xG or xA in 10 and 7 of the 16 games, including 5 games with zero in both, in which he has played versus Rangers since their return to the Premiership!

Forrest is probably performing at the highest level of his career and in a relatively consistent way. Let’s hope that Forrest continues to be such a consistently good player – but maybe he could use a rest when we go to Ibrox in March.