The Angel-Devil game is played on an infinite chess board. In each turn the Angel jumps from his current position to a square at distance at most k. He tries to escape his opponent, the Devil, who blocks one square in each move. It is an open question whether an Angel of some power k can escape forever.
The mechanics are obviously different from it, but the theory kinda of still applies: if we limit the pieces to the maximum of K squares, could it lead to a checkmate?
In late 2006, the original problem was solved when independent proofs appeared, showing that an angel can win. Bowditch proved that a 4-angel (that is, an angel with power k = 4) can win[2] and Máthé[3] and Kloster[4] gave proofs that a 2-angel can win.
Somehow it reminded me of The Angel Problem:
The mechanics are obviously different from it, but the theory kinda of still applies: if we limit the pieces to the maximum of K squares, could it lead to a checkmate?
That’s neat, I’d never heard of it before!
Looks like you’re quoting the Proceedings of 11th Annual International Conference on Computing and Combinatorics from 2005: https://dl.acm.org/doi/abs/10.5555/2958119.2958180
Apparently, it was solved (twice!) the next year.
https://en.wikipedia.org/wiki/Angel_problem