Over at Cards Conclave today Doug made a post about who plays and strikeout rates and that got me started. This was supposed to be a simple few paragraphs about why strikeout rate is an overvalued metric of player ability in most cases, but after running across some numbers it became more. The discussion was focused on three players and who should play between **Matt Adams**, **Brandon Moss**, and **Jeremy Hazelbaker**. But since 140 characters makes it difficult to have a discussion…

As of this morning, Adams and Moss have a 30.7% K rate and Hazelbaker’s is at 29.9%. So over 600 plate appearances (generally considered a “full season”), Hazelbaker will strike out 5 fewer times. That’s hardly moving the needle. The three of them have the three highest strikeout rates on the team, so it isn’t like we’re debating between that 30.7% K rate and **Aledmys Diaz**‘s team leading 8.9% K rate.

I’ve been fairly vocal of my opinion of strikeouts over the years. They get a bad rap. Getting one out by swinging through a ball is far better for the team than getting two outs with poor contact.

So ultimately, making good contact with the ball is far more important. I think most everyone would agree, but I do understand why some use K rate as an inverse measure of contact rate. The logic is sound that if you’re striking out a lot, you may be having trouble squaring up the ball.

But no longer do we have to rely on a rudimentary logic jump to determine just how well players are hitting the ball.

We can look at ground ball rate. Matt Adams has a 27.0% ground ball (GB) rate, Moss has a 29.4% GB rate, and Hazelbaker has a 58.4% GB rate. That’s astoundingly high. That means almost 60% of the time Hazelbaker hits the ball, it’s on the ground. League average runs about 45%.

We can also look at line drive rate, which is a great measure to see how well a player is squaring up the ball at the plate. Matt Adams has a 29.7% line drive (LD) rate, Moss has a 21.6% LD rate, and Hazelbaker has a 15.2% LD rate. League average runs about 21%.

Just by that metric alone, when Matt Adams makes contact, he hits the ball hard twice as often as Jeremy Hazelbaker does. That is a meaningful difference.

But how much of a difference?

Line drives, of all the batted ball types (ground ball and fly ball being the other two) have the greatest odds of ending up as a hit. I wasn’t able to find 2015 or 2016 numbers in a quick search, but in 2014, the league had a .685 batting average on line drives and just a .239 batting average on ground balls (and .207 on fly balls for reference).

Further, when you do some math you find that a line drive produces 1.26 runs per out while a ground ball produces just 0.05 runs per out.

And when you take all of that in, it becomes pretty clear that Hazelbaker’s odds of continuing to out produce either Adams or Moss are pretty slim. Some of Hazelbaker’s early success can be attributed to pitchers learning him, but now they are finding out where his weaknesses are and that strikeout rate is rising.

Over the season’s first 10 games, Hazelbaker hit .419 with 3 home runs and a 24% K rate. In the 19 games since, he’s hit .216 with 2 home runs and a 35% K rate.

But that realization is not nearly as much fun as claiming Matheny is incapable of understanding this and is just playing favorites, right?