Proofread the following extract and correct any errors in verb tenses.

Correct the two errors in these paragraph:

"For years, Go was considered the last redoubt against the march of computers. Machines might win at chess, draughts, Othello, three-dimensional noughts and crosses, Monopoly, bridge and poker. Go, though, is different.

The game required intuition, strategising and character reading, along with vast numbers of moves and permutations. According to legend, it was invented by a Chinese emperor to teach his subjects balance and patience: qualities unique to human intelligence."