spywaregorilla left a good reply about Starcraft. In the games I watched, despite the AI being handicapped to use human-like levels of APM and human-like viewport management, it primarily fought using *clearly superhuman* blink stalker micromanagement. Stalkers with barely any health would typically survive engagements and get to re-engage when their shields were fully recovered. On the other hand, a human player managed to confuse the bot by repeatedly airdropping units in its base, picking them up, and dropping them elsewhere. The bot uselessly moved its mass of stalkers back and forth while losing many probes and buildings.

Edit: After looking at some games again, the AI also benefits from precise target selection for the phoenix's graviton beam. A human player might take 3 phoenixes and a bunch of stalkers into a fight against an army containing 3 immortals, some sentries, some stalkers, and some zealots, and use graviton beam to pick up some mix of units including units other than immortals. The bot can pick up only the immortals.