Good question. (Though you're a young whippersnapper to me!) I'm not much of an expert on modern metrics, but WPS is one that I think is quite useful in measuring "clutch hitting."
Win Probability Added measures how a player's at bats changes the estimated probability of his team winning the game. To take an easy example, starting the bottom of the ninth tied, the probability of the home team winning is, maybe, 0.6. (It's greater than 0.5 because the home team still has the 9th to score but the away team does not. It would be 0.5 at the beginning of the top of the 9th.) If a player hits a lead-off homerun, that probability rises to 1.0---the game is over and the home team has won. By increasing the win probability from 0.6 to 1.0, the batter gets credit for 0.4 win probability added. (And the opposing pitcher gets -0.4 because he allowed the home run, lowering his team's win probability from 0.4 to 0.0,)
I find it a very useful statistic because it gives credit for hit that are important to the team rather than first-inning solo homers that don't change the probability much.
In the case of Cave, his at-bats in the last two games have increased the Twins' win probability by nearly one, which is huge. Crudely, without his at-bats the Twins would have on average lost one of those two games.
I don't know the origins of that particular statistic, but 20 years ago I came up with the concept on my own. I had no access to the probabilities required (0.6 in my example) to put into into practice, but I was excited to find that someone with time and access had done so. I use the numbers from https://www.fangraphs.com/, though I believe there are alternatives.
I hope I've been clear. No one statistic is a complete representation of a hitter's value, but I think WPA does tell us something important.