LAS VEGAS — After the Las Vegas Aces flummoxed the Phoenix Mercury in the second half of Game 1 by going to a zone defense, much of the Mercury’s emphasis on Saturday was how to counter the Aces’ zone. In the first half Friday, the Mercury repeatedly ran inverted pick and rolls for Alyssa Thomas, just as they had done so all postseason. Once the Aces showed help, Thomas was then able to kick out to open shooters for 3-pointers or easy looks at the basket.