Clutch hitting has always been the awkward cousin of sabermetrics. As a stat, clutch hitting doesn't have much predictive value. A player's overall stats are much better predictors of future clutch performance than his current clutch performance.
One important thing to remember about sabermetrics is not all statistics have to tell you who is better. Stats can also be descriptive and tell stories about what happened.
Felix Hernandez's 13 wins in his Cy Young season don't accurately evaluate his performance, but they give an account of events that took place. He was a great pitcher on a team that provided shoddy run support. Clutch stats are like this too, and in the 2016 season, no player was more clutch than Cleveland's Jose Ramirez.
One popular stat for looking at clutch-related issues is WPA, Win Probability Added. It's a stat of simple design, as it takes the probability that a player's team wins, both before and after his plate appearances, and credits the player the difference. If you look at the list of WPA leaders, you'll see the usual cast of sluggers: Josh Donaldson, Anthony Rizzo, Joey Votto, Mike Trout, etc. But you'll also see a name you wouldn't associate with one of the most dangerous hitters in baseball: Indians third baseman Jose Ramirez.