Ibaka had been uber-efficient this postseason, shooting 61.6 percent from the floor while also knocking down 4-of-11 from long range and hitting 85 percent of his foul shots.
But where Ibaka holds the key for the Thunder is his work protecting the rim at the defensive end. Ibaka was averaging 2.2 blocked shots per game in the postseason. That’s down from his 2.7 blocks a game during the regular season, but that reduction came in part because the Memphis Grizzlies and Los Angeles Clippers both game-planned to try to avoid challenging the shot-blocker extraordinaire at the rim.
Set to begin the Western Conference Finals against the top-seeded San Antonio Spurs on Monday, the defensive numbers tell a sobering tale about OKC’s chances without Ibaka protecting the paint.
In their 4-0 sweep of the Spurs during the regular season, Ibaka blocked four shots per game and of 22 shots the Spurs had blocked in the restricted area, Ibaka had 15 of them.
With Ibaka on the floor against San Antonio, Oklahoma City surrendered 93 points per 100 possessions.
With Steven Adams on the floor, that number shot up to 106. Nick Collison had an even more detrimental effect on the Thunder defense—the Spurs scored 110.2 points per 100 possessions when Collison was playing.
Kendrick Perkins’ defensive rating against San Antonio was 89.9, but almost all of that time on the floor came when paired with Ibaka.
The choices for the Thunder are not encouraging. Collison and Perkins together would rely on Perkins to be the primary rim protector.
Of the group of Adams, Collison and Perkins, the Thunder would be trying to guard a power forward with great passing skills and deceptive quickness with players who could be accurately labeled as slow, slower and slowest.
The Thunder will have to change their entire defensive philosophy to make this work. Perimeter and wing defenders have had the luxury of gambling, secure in the knowledge that Ibaka was there to erase penetration at the rim.
Can Oklahoma City change to focusing on help positioning and funneling traffic away from the restricted area? Sure. Can they do it by Monday? That remains to be seen.
Without Ibaka on the floor, Oklahoma City limited San Antonio to 53.3 percent shooting at the rim—a solid performance—but those numbers are based on only 30 shot attempts over 44 minutes. The Thunder’s defensive rating in those 44 minutes? A ghastly 120.8.
San Antonio was one of the most efficient teams in the NBA in the restricted area, with their 64.8 percent conversion rate ranking third in the NBA.
Against the Thunder, however, the Spurs made only 50.4 percent of their shots at the rim. But most of that number came against an Oklahoma City team fortified by Serge Ibaka ranging the restricted area.
Not having him will leave the Thunder vulnerable to San Antonio’s penetration and their kickouts to open shooters at the 3-point line.
All stats from NBA.com/Stats.