 Type A programs would use a "brute force" approach, examining every possible position for a fixed number of moves using the minimax algorithm.Shannon believed this would be impractical for two reasons.First, with approximately thirty moves possible in a typical real-life position, he expected that searching the approximately 109 positions involved in looking three moves ahead for both sides (six plies) would take about sixteen minutes, even in the "very optimistic" case that the chess computer evaluated a million positions every second.