Anti-Phase Game Strategy


An anti-phase game strategy is often required to win in two-person sports. When we first learn any two-person sport we are usually uncoordinated at first. In a ‘sport’ like ballroom dancing we very quickly learn to get our movements in anti-phase with the other person. It matters not which role who is playing predator (moving forward) or prey (moving backwards). Alternating that phase relationship may result in severe digital consequences.

Experts will intuitively move to be coordinate phase, not just in ballroom dancing, but also in games such as tennis when long rallies develop. Not counting shot misplacements, such rallies are usually won by the player who moves to change the phase condition by moving in a different direction to place the ball in a position unexpected by the opposing player.

Kijima et al set out to study the way the dynamics and phase relationships develop in a two-person game and they present their information in yesterday’s PLoS ONE (1). They chose their university soccer team to learn a new game. (The goalie was left behind to tend his net.)

The game they had to play was called Play-Tag. It is played in a 5m square ring. (Why a square is called a ring is a subject for another day.) Each player has a chunk of nylon fabric Velcroed to each hip. The players have to rip off one of the tags of their opponent to win.  The game can be played to exhaustion. The experimental program consisted of 10 trials for each pair.

At first the players were uncoordinated as they played predator and prey and tried to work out the best strategy – should they minimize the risk of losing a tag or maximize their chance of gaining a tag?

These were all smart, able sportsmen who are used to anticipating teammates and opponents movements, but it took most of the trials before a general strategy evolved. The movement of the pairs ended up in an anti-phase coordination as the strategy to minimize their risk of loss took precedence. The result was that the anti-phase game strategy moved towards deadlock and long games.

Predator-prey alternation occurred with the players choosing a strategy in with neither have anything to gain by only changing his own strategy ­ if he does the risk is too great, hence the deadlock until a mistake through something like fatigue occurs.

These sorts of insights into game theories have applications to all sorts of other activities such as business negotiations. Even election politics when deadlock comes to the surface.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0047911

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