When done with the proper personnel, switching on screens is arguably the most effective strategy to defend the pick-and-roll. It essentially negates the advantages created for both the ball-handler and the roll-man; however, switching can come with its liabilities, too. The easiest way to exploit a switching defense is to create mismatches that are favorable for the offense. For example, there are very few NBA big men who can capably defend average starting point guards in isolation. There are even fewer who can guard Russell Westbrook in space. The Rockets' decision to switch nearly every pick-and-roll down the stretch led to some crucial Thunder baskets, and ultimately to an Oklahoma City victory.
These first two possessions take place in the second and third quarters respectively. Houston power forward Ryan Anderson is a notoriously weak on-ball defender, and that's why it's so surprising that the Rockets are seemingly comfortable switching him onto Westbrook. Granted, in both of these situations, Anderson kept Westbrook out of the paint, coaxing him into semi-contested mid-range jumpers. Usually, defenses will gladly concede mid-range attempts to Westbrook, who shot just 36.3% on such shots during the regular season. Though he took the third most mid-range shots in the league this year, his efficiency ranked 47th among the 51 players to take at least 250 mid-rangers.
However, in Game 3, Westbrook nailed seven of his 13 attempts (53.8%) for 14 points. This could be because guys like Anderson and Capela have to sag off Russ to defend the drive, and allow him too much space to rise and fire. It could be because Westbrook just feels more confident when bigs are trying to defend him. Or it could have just been dumb luck.
On this play, with OKC up by three and just under two minutes left to play, Russ gets Anderson to switch onto him again. This one feels like Houston conceded the switch far too easily. Westbrook isn't attacking downhill off the screen, and there is plenty of time for Anderson to hedge and for Gordon to get back to his man. The best move would have been to force the ball out of Westbrook's hands and make a different player beat you. Sure, Gibson had it going all night long, but Trevor Ariza made his rotation to take away that option. If the Thunder beat you on a Jerami Grant three, you tip your cap. Switching in this circumstance played exactly into the Thunder's hands and gave them the matchup they wanted without putting up much of a fight. Westbrook was easily able to take advantage.
This possession ended up being the deciding play of the game. In it, Ariza gets caught on a great screen by Steven Adams, causing Nene Hilario to switch onto Westbrook. However, it was actually the other mismatch created by the switch that proved to be the deciding factor. Ariza was unable to handle Adams on the box out and gave up the game-winning tip-in for the Thunder.
Given the Rockets' defensive personnel, switching the 1-4 or 1-5 pick-and-rolls is not an effective strategy to contain the Thunder's offense. Oklahoma City will not have the firepower most nights to score enough points to contend with Houston. But, if Houston does not change up their pick-and-roll coverage, Oklahoma City can continue to exploit any mismatch they want.