Abstract. Progressive Pruning (PP) is used in the Monte-Carlo go playing program Indigo. For each candidate move, PP launches random games starting with this move. PP gathers statistics on moves, and it prunes moves statistically inferior to the best one [5]. This papers yields two new pruning techniques: Miai Pruning (MP) and Set Pruning (SP). In MP the second move of the random games is selected at random among the set of candidate moves. SP consists in gathering statistics about two sets of moves, GOOD and BAD, and it prunes the latter when statistically inferior to the former. Both enhancements clearly speed up the process on 9 × 9 boards, and MP improves slightly the playing level. Scaling up MP to 19×19 boards results in a 30% speed-up enhancement and in a four-point improvement on average.