scrabble player who earns their points by adding an "s" or "d" to the end of a high scoring word belonging to another player.
or a player who blocks off certain high point letters or triple word squares, just to prevent the other players from using them.
In general, any practice by a scrabble player that is allowed by the rules, but just seems like an unfair sheist.
Player one: A M A Z E. Ha- double word score, 32 points.
Player two (adds an 's'): A M A Z E S! Double letter AND double word, 34 points.
Player one: You Scrabble Sheister!