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Ordering matches against a strong and weak rival

Question

You will play three tennis matches in a row, alternating between two opponents, and you take the title if you win two matches in a row at some point. One opponent, Alice, is harder to beat than the other, Bob. Should you choose the order Alice–Bob–Alice or Bob–Alice–Bob? Reply 11 for Alice–Bob–Alice and 22 for Bob–Alice–Bob.

Short answer

1 (Alice–Bob–Alice). Two consecutive wins are impossible without winning the middle match, so you want the easier opponent there. With win probabilities x<yx<y against Alice and Bob, the chances are 2xy−x2y2xy-x^2y for ABA and 2xy−xy22xy-xy^2 for BAB, and the first is larger.

Adapted from QuantQuestions.io; question and answer rewritten by SelfMadeQuant.com.

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