I see that the .878 you quoted was the Pool-Trax "Performance Rating." That is different from an Accu-Stats TPA, and I have not been able to learn exactly how Pool-Trax calculates theirs. The Accu-Stats TPA is balls pocketed divided by the sum of balls pocketed and errors. By my notes, Efren pocketed 208 balls (I could be off by a couple). If the TPA were .878, that would imply 29 errors of one type or another. But, as noted, the .878 is not the TPA.
Anyway, I agree -- Efren played a terrific match.