Right Brain for Chess?

Introduction

In this study I set out to examine the impact of set-ups designed to prioritize the use of one half of the brain over the other on my chess performance. The concept of the study was informed by differences in the function of the two brain hemispheres, best described by Ian McGilchrist in The Master and His Emissary. The aim ultimately was to determine if my own play might be better when focusing with one hemisphere, which could possibly explain my varying results under different circumstances. And, maybe, to answer the age old questions; is chess art or science?

Background

I first began playing chess, like many others, in late 2020. Prior to that I had almost no experience with the game, other than a vague idea of how the pieces moved. Almost immediately, I was hooked. It hit all the buttons for me, there were books, there was language, there was history, there were stats (a surprising finding!), but what maybe what struck me the most was how it offered this fascinating look into how our brains worked and how we learned. And I wasn’t alone; there was a whole community of people out there talking about this very thing- how best do we learn?

Unlike my obsession with chess, my interest in handedness and brain function has been brewing for a long time and comes from my relatively unique individual experience. It is unclear if I am truly ambidextrous, or just a natural left-handed person that was forced into right-handedness at an early age. I was raised not just to play baseball, but to be a shortstop and there simply is no such thing as a left-handed shortstop. And to be fair to my dad, who as a lefty believed the world was set against him, there is no place I feel more comfortable or would rather be than taking the field at shortstop. So, I was forced to throw and write right-handed, while in other sports, like tennis, ping-pong, etc. I was free to be a lefty. It wasn’t until high school that I began to write left-handed. It was, perhaps, an act of rebellion. Maybe the most low-key teenage rebellion of all time. Nonetheless, I didn’t “come out” as left-handed to my parents until well into my 30s. It is always on my mind, handedness, and it is fair to say that the first thing I notice when I am in a conference room full of new people is what hand they write with, a fact about them I’m far more likely to remember than, say, their name. I feel different when holding a pencil, a fork or a tennis racket in my left hand. Not just that performing the task left-handed feels different, but different in my whole sense of being. I feel simply better when moving through the world as a lefty. I recognize this is weird.

While the pop-science notions of left-handed people being creative and right-handers more analytical, etc. have largely been relegated to the realm of pseudoscience, there are true differences in how the hemispheres function and process information. The most obvious example of this fact that most people would be familiar with is the fact that the language center of the brain is located in the left hemisphere of the brain. A stroke damaging that part of the brain will impair a patient's ability to speak, whereas a stroke in the right will leave that function intact. But the differences go far beyond that. The right hemisphere (which controls and receives input from the left side of the body) processes information more holistically than the left, which tends to break things down to parts, categorizing and naming. The left hemisphere is the trees, the right the forest. The right is flow and motion, the left is fixed detail. From these real differences we get the notions of the creative vs. the analytical. To avoid getting sidetracked here, I point you to Ian McGilchrist’s book The Master and His Emissary, or if you are really up for a challenge, the two volume The Matter with Things. (Naturally, I learned of McGilchrist via the GM and Philosopher Jonathan Rowson).

So, it is very natural for me to wonder about the impact of handedness on chess. The first form this notion took was to just naturally assume as a lefty I should play 1.d4. I can’t stress how obvious this seemed to me. When I went to try and find some intel on this, I couldn’t. I posted on either a message board or twitter, and the general consensus was that that was an absurd thought and I didn’t get a single response seconding my experience (although Sam Shankland is a left-handed d4 player, so, that’s something). Nor could I find much information about whether or not lefties were over-represented in the chess world, or even who was left-handed. Turning away from handedness to talk strictly about brain hemisphere function, a case could be made that the primary function of each hemisphere has its place in high-quality chess and I could see passionate arguments for either side. Do you need flow and a holistic picture of the game? Or do you need knowledge of detailed fixed positions? Maybe it depends on the type of player you are. Creative, attacking players vs. the more positional ones may rely on different parts of the brain. And I can’t help but note, pseudoscience aside, Tal and Dubov are both lefties. Intuition or memorization? Art or Science? An age-old debate, that perhaps comes down to individuals. One of the things I came to love about chess is the fact that the game could accommodate many types of personalities, despite the stereotypes to the contrary.

Another interesting neurological finding was that I seemed to play significantly better when either sick or under the influence of various substances, such as NyQuil or cannabis (legally acquired and for, ah, sleep). I haven’t yet performed a study to truly verify this, but it seems to be holding up, particularly in the faster time controls. There is plenty of anecdotal evidence of people claiming to play better, at least in blitz or bullet, when a little bit drunk, but playing better while sick or high seemed a bit out of the norm, although not unheard of. In wondering what the difference was for me, I naturally began to wonder if THC was potentially impacting one brain hemisphere more than another, freeing me up to be my best.

So, I set out to 1) try an experiment to determine if I play better when primarily engaging the left hemisphere of my brain, or the right and 2) to try and research the differential impact of cannabis on the two brain hemispheres. Unfortunately, in regards to #2, I wasn’t able to find much as most of the research appears to be focused on long term impacts of brain structure, as opposed short term changes. I did, however, manage to perform a perhaps dubious experiment to determine the left-right brain question.

Methods

I played a series of games (108 in total) divided equally among the following three conditions: left eye closed and right-handed mouse use, right eye closed and left-handed mouse use, and normal (both eyes open and right-handed mouse use).. Unfortunately, unlike the function of hands, the situation with the eyes is a bit more complicated. It isn’t merely that the left eye maps to the right hemisphere, but the left visual field of each eye. So, closing the right eye alone doesn’t mean you are using the right hemisphere. To account for this I attempted to not only close the right eye, but also to sit sideways and look askance at the board to put it in my left visual feel and vice versa. I also attempted to use the mouse left-handed during the left eye open games. I think for the “split brain” patient experiments (worth reading about in their own right because I think they hint about things that really alter our perception of reality and the nature of thought) they must have used some sort of device to isolate images in the left or right visual field. Obviously, I wasn’t able to do that, so the whole experiment may be wrong from the start and just silly, but for the sake of fun, let’s just assume the experimental design accomplished its goal of leading to thinking with predominantly one hemisphere or the other. Worst-case scenario, I played 108 games of chess and got to occupy my mind by writing this article in during what was a stressful and emotional time in my life (my 18-year old twins, who have Asperger’s and considerable anxiety, leaving home for the first time to go live at a transition program to prepare for college).

All the games were 10+5 Rapid games played on Lichess against random people. At the beginning of the study my Lichess Rapid rating was 1555 and during this timeframe (about a month and half) hovered between 1510 and 1580 or so, which is about where it has been for the last six months or so and the experiment ended with my rating at 1561. I did no chess study or “adult improving” during this period and I kept with the same openings throughout the study (for those interested in openings, and who isn’t, Queen’s Gambit with white and Scandi and Dutch as black). Generally, I would play three games in the morning, which is sort of my routine, one with each condition. I did not systematically approach which condition would be used, but tried to vary it fairly. I also didn’t account for having the black or white pieces at all, although my results are historically little impacted by that.

I tracked the results, but also the Accuracy and Average Centipawn Loss for each game. An overall performance rating was calculated for each condition, as well as the average accuracy and ACPL. The Accuracy and ACPL were compared used a T-test to determine the statistical significance of the results.

Results

Table 1 below includes the results for each of the three conditions and Table 2 shows the statistical analysis comparing the results using a two-tailed T-test.

Table 1: Results by Condition

Table 2: Statiscal Analysis

Discussion

The results indicated that the level of my play was in fact better with only the left eye open and left-handed mouse use, thus employing the use of the right hemisphere of my brain. The results indicate a performance rating of 1634 vs. 1548 and 1464 in the other conditions. The difference in ACPL vs. control (54.1 vs. 68.6) was statistically significant with a p-value of 0.04 (indicating that there is only a 4% chance these results could have been randomly generated). When comparing the left-hand mouse vs. the other two conditions using the mouse right-handed approached a significance of <0.05 at 0.06. This would potentially suggest I’m at my best when being a more intuitive player. However, these results should be taken with several grains of salt, described below.

Bias

Naturally, these results were cool to me. I fancy myself an aggressively attacking creative genius, like Tal but if he was pretty bad at chess. I definitely prioritize winning with style over simply winning. I don’t memorize openings. And generally I also want to come down on the side of being more left-handed than right-handed, as discussed above.

So, the obvious question (aside from the most obvious question of whether or not the whole experiment was stupid from the outset), is; was I biased? It is certainly possible, as I was the one who both designed the experiment and was the subject of it. However, all the games were rated games and I, like all of us chess players, really don’t like to lose rating regardless of the reason. So, I can say that I did certainly try my best in all the games. Also, being a fiercely competitive child who had quite a lot of alone time, and growing up in the 1980s pre-video game and internet, and also being ambidextrous, I have a lot of experience playing games pitting the right hand vs. the left. Whether it was darts, or free throw shooting, or playing tennis against a brick wall, I spent a considerable amount of time playing left vs. right. Always, I wanted the left hand to triumph, but yet always managed to maintain as fair a competition as possible. So, this experiment wasn’t a unique experience for me, and I think I handled it fairly, but bias can be tricky to root out.

Underperformance of Control

The performance rating of the control, 1464, was a good bit below what would be expected given my rating of 1555 at the start, which potentially clouds the data. I expected a series of 3 x 36 games would be enough to be representative, but perhaps not. One explanation is that during the “control games” the relief of having both eyes open and using the mouse the way I typically do I simply “relaxed” a bit and lost some level of focus leading to a worse than normal performance. However, the ACPL for the control games, 68.6, was pretty similar to my overall ACPL over the past six months, 66.4 and the difference between the left eye and control games ACPL was statistically significant.

Results Unique to Me

For several reasons, these results may only apply to myself and not indicate broader implications of left brain vs. right brain play. Firstly, even if true in my case, the results may only apply to my unique state of play. I’m not great. I tend to overperform against people of stronger levels while being able to lose to people well below me in rating. I make far more glaring blunders than would be expected at my rating and that is the chief decider in most of my games. So, theoretically, the right hemisphere maybe sees a broader picture that helps avoid these blunders, as opposed to a microfocus on my own attacking plan led by the left hemisphere. If true, this would be a meaningful and impactful finding for myself. I also have a fairly unique neurological history. The ambidextrous history, the change over time in my handiness (which also sort of coincided with a couple childhood seizures, interestingly) might just mean I’m messed up in the head and this truly works for me, but would not apply to others.

A Quite LIkely Alternate Explanation

Playing with one eye closed while looking sideways at the screen and using a right-handed mouse left-handed is a pain in the ass. And that might be the whole benefit. As mentioned above, my losses are frequently based on howling blunders impulsively made in split seconds, regardless of the time left on my clock. The simple act of creating some annoyance might have been just enough to slow me down. Additionally, with one eye closed it did feel slightly more difficult to see the whole board and maybe the act of consciously looking around at the whole board I picked up things that normally I might overlook, thinking I’m seeing the whole board when I really am not. This could also explain why the right eye open performed slightly better than the control and the left eye only wasn’t statistically significantly better than the right eye alone. I suspect I could get similar results playing with a neck brace or glasses with the wrong prescription. This potentially slowing down or putting a check on my impulsively disastrous moves might also come into play when slightly high or in a NyQuil haze at 3 a.m., tying together that piece of the puzzle.

Accuracy vs. Average Centipawn Loss

Both these measures have their own problems in regards to the evaluation of chess performance.. Interestingly, the impact on ACPL was more pronounced, with a p<0.04 value comparing the left eye open to control, and nearing significance when comparing the left eye open to right eye open. If the only real difference was the prevention of howling blunders then it might be expected that the impact to ACPL would be greater than the difference to accuracy, if I understand how those measures work, which may or may not be true.
Left-Handed Mouse use

Possibly the whole eye-closed aspect of the study was less important than the use of the mouse. There is some evidence to say that decisions are made in the brain before we are aware of them, that motion acts alone. A study in the 1980s by Libet found that the unconscious brain activity leading up to the conscious decision by the subject to flick their wrist began approximately half a second before the subject consciously felt that they had decided to move. This along with some results from the split-brain experiments seem to suggest that what we think of as “thought” is more a made up explanation by the language of the left hemisphere that takes place after the fact. A truly mind-blowing finding. If true, the left hand at the direction of the right hemisphere may be acting in ways that are unclear to the language making left hemisphere. And therefore, may play chess differently. In interesting question could be put to Levon Aronian, who is right-handed, but moves the pieces with his left. I’m dying to know if he uses the mouse right-handed and if he feels his on-line play is different than OTB. These thoughts are pretty out there, so feel free to just ignore this part.

Regardless of the broader implications or validity of the results, I remain interested in the topic. I’d love to hear the experiences of other and about any knowledge (like a good list) of left-handed chess players or any research regarding the impact of THC on different parts of the brain.

And if you ever see a guy at a chess tournament wearing an eye patch he didn’t show up with and sitting sideways at the board, feel free to say hi.