Juerys Familia spoke to reporters after the loss to the Yankees in which Familia pitched a scoreless ninth inning. He told reporters that the Mets coaching staff has shown him videos of last year and was explaining that he had an 84% extension.
This season his extension percentage is at 75-77 and is believed to be the reason of his struggles.
“I was finishing a little bit too short. So with me finishing short, I was letting the ball go too early… This is the best outing I’ve felt all year”
I’m not too sure what an extension percentage is but I’m guessing it has to do with his release point in his delivery.
Source: Matt Ehalt