War Strategy and Soccer: is a War of Attrition or a Perfect Strike Better for Winning?
/By Sam Goldberg (@samgoldbergTHFC)
For the purposes of this article, we’re going to define a soccer game through the lens of the home team. It’s their turf, their fans, and their local pride. More importantly, the home team generally chooses the style of gameplay that will occur. This is dubbed “Home Field Advantage.” Home Field Advantage is backed up through data analysis as well, as MLS home teams generally win 53% of games season by season, higher than most every other league in the world.
War is the same way. The home country generally decides the style of fighting; Guerilla Warfare like Che Guevara, or a Battle of Attrition like the French in World War I? This is dictated by a clear strategy coming from the leadership at the top, as well as knowing the local land and intricacies of the surroundings, combined with the technology and mindset of the time.
So if you are an MLS coach, your squad’s general, and you have a decision to make on how to structure your game strategy for home games, how do you want to structure your battle? Do you want to attempt to strike at the perfect moment, or do you want to constantly bombard the team with shot after shot? Do you want to wait patiently because you know you will get a few really good opportunities, or do you want to constantly attack no matter the location, even though you don’t know whether or not with relative certainty that the attack will have an overall effect on the end result of the game.
Another question that arises from this is whether or not the perfect strike actually exists. Is there a moment in time in the game where a goal is so deadly that it makes it incredibly hard for an opposition team to come back? If so, is it worth it for the team to play in this style instead of trying to bombard the team with as many shots as possible throughout the entirety of the 90 minutes? These are the questions which will be discussed and answered below.
Definitions
For the purposes of this article, we will define a game using two different battle terms: a Battle of Attrition Game and a Perfect Strike Game. We will define a Battle of Attrition Game as a game where the home team takes many shots with relatively low efficiency on those shots (taking many shots but not necessarily from good areas). We will define a Perfect Strike Game as a game where the home team takes a relatively low number of shots with relatively high efficiency in those shots (not taking many shots but shooting from good areas). We will define efficiency as expected goals (xG) per Shot taken (xGPerShot) as a way to illustrate the average value of every scoring chance taken in a game. We will also analyze the timing of these strikes throughout the game to try to determine if an early strike or a later strike is more beneficial, and weigh the risks of each.
War of Attrition
With a War of Attrition, we are looking for games in which teams take many shots with under the average xG per shot. The graph below should help to visually illustrate any trends that may arise.
Initially, we can see that a high number of home team shots and a low xGPerShot for the home team (bottom right quadrant) yields mixed results. In games where the home team took over the average number of shots for an MLS team (14.89 shots per game) and had under the average xGPerShot of 0.1219, they only won 39.48% of the time. This is less than the average amount that teams generally win at home. This seems like a poor strategy to undertake for teams, however, a Perfect Strike Game needs to outperform a Battle of Attrition game in order for one to be generally considered more favorable than the other.
Perfect Strike Game
If MLS teams taking many inefficient shots is actually hindering their chances of winning, will a team shooting from better areas fewer times actually help them more?
Initially from the graph it appears that a low amount of shots with a higher xGPerShot will yield better results, and the raw numbers would agree. Teams that took fewer than 14.89 shots per game and averaged over 0.1219 xGPerShot won 68.79% of the time. Furthermore, in games where the team played in this Perfect Strike style, they only lost 14.5% of the time. This is over a 15% increase from the 53.0% average home team win percentage that we started with.
Is the Combination of a War of Attrition and Perfect Strike Strategy the Most Optimal?
While measuring the opposite sides of the spectrum have yielded results that found that the Perfect Strike Strategy is more optimal than a Battle of Attrition for MLS games, more research is needed on if a team is actually able to achieve both a war of attrition and a perfect strike game, and if this is a sustainable strategy to keep throughout a season. In games where the home team had great than 14.89 shots and higher than 0.1219 xGPerShot, they won 76.5% of the time. This is just above a 6% increase from playing a solely Perfect Strike Strategy. While in a purely numbers sense this is the most optimal, it does not necessarily mean it is the most realistic, as home teams only get above these thresholds 20% of the time. Because of this, it can be concluded that home teams should always try to take the highest number of high quality strikes possible, but if they cannot get a high number of high quality strikes, they should rely more on the Perfect Strike strategy, rather than settling for a high number of lower quality shots.
The Timing of The Perfect Strike
Unlike war, soccer has a predetermined time limit that will never change. This allows us to measure the best window of time for a team to score in that will make the most difference in the final outcome of the game.
The answer to this question has to depend on the game script, or the current score differential and the run of play. For example, a team that is up 3-0 and scores in the 89th minute, that goal will not have the same effect as a goal scored in a 0-0 game in the 89th minute. These factors will be forever changing and live data on the current game state can help coaches make informed decisions on when to push for that elusive goal. Because of the complicated nature and near infinite possibilities of game states, we will be looking at the opening fifteen minutes of our battle and posing the question: is it worth risking it all for a perfect strike in the first fifteen minutes, even if it possibly opens you up to a strike against you?
As a reminder, 53% of all games are won by the home team in MLS. If a team is successful in finding that perfect strike and is up by a single goal at the end of the first fifteen minutes, how much does it increase their chances of winning? According to our calculations, since the beginning of the 2017 season, home teams that have scored in the first 15 minutes of the game have gone on to win 73% of the time, while only losing 11% of the time. However, if the home team is too aggressive in the first fifteen minutes and goes down a goal, they have only won 33% of those games. It should be noted that the away team has only scored in the first 15 minutes of the game 11% of the time in MLS since 2017.
Conclusion
MLS is an interesting league, it constantly bucks trends of leagues around the world, it plays during the hot summers and the beginning and ends of cold winters, and the results are often random in nature. Having a concrete methodology, game model, and strategy, can help smooth out this randomness and constant questioning about why certain game play did or did not work. The results above illustrate two things that are concrete in nature in MLS and presumably, across the world: score early, and don’t shoot often from areas that are not inside the box. This will give your team a better chance of achieving that perfect strike and winning the battle at hand.