had all players adopted the Nash strategy. In both cases the researchers found typical psychological patterns in the finer structure of the numbers chosen. In the Swedish "Limbo" game, a number of players appeared to have disproportionately chosen particular favourite numbers, such as their year of birth. On the other hand, players apparently sought to avoid particular "focal" numbers, such as even numbers or round numbers divisible by 10, in favour of odd numbers or prime numbers -- although Östling et al found that after 49 rounds of their smaller game, the tendency to disproportionately choose odd numbers became almost eradicated. Similar games A similar game is Guess 2/3 of the average, where the optimal strategy depends on the actions of the other players. See also Bidding fee auction, another auction scheme in which bidders pay for entry Online auction References Types of auction