Randal Grichuk, Harrison Bader and Tommy Edman

From the moment Tommy Edman joined the team this summer, he was something of a folk hero. He showed a penchant for big moments early on, and while his underlying numbers were sometimes a little soft, he finished the season with a team-best 123 wRC+. He ranked 3rd in WAR among position players, despite amassing 100 and 200 fewer plate appearances than the leaders.

That’s what Tommy Edman did in 2019, and it’s hard to see the Cardinals making it to the NLCS without his production. But it’s important not to simply assume what he did is what he will do going forward. That’s a mistake the Cardinals have made too many times in recent years.

When I think about Tommy Edman and his sterling half-season debut, I can’t help but think about Randal Grichuk and Harrison Bader. Both of those players roared on the scene with results that outpaced their underlying numbers. In both cases, the Cardinals made a place for them going forward. And neither one of them has lived up to those first half-seasons.

Here’s a look at some relevant numbers from the seasons in question:

There’s a lot of similarities here. In each case, we’ve got a little more than a half-season. That’s just enough to lull us into thinking we’re looking at a bigger sample size than we are. This is still Small Sample Size Territory. Each player posted an offensive line that was above league average, and much better than what anyone projected in their debut.

Harrison Bader broke just barely into the MLB Pipeline at #90 in 2017, but in general none of these three were “Top 100” type players. They were each projected to be something more like role players. They debuted midseason not to any real fanfare, but simply because there was a hole on the roster and they were the next man up. And then they each outperformed expectations.

What should concern us is that the similarities don’t end with the raw production. They carry over to some important underlying numbers, which in each case should (or should have) given us pause.

I like to look at these three stats - Walk Percentage, Strikeout Percentage and Batting Average on Balls in Play - to get a handle of how luck and skill balance out in a player’s performance. Every Plate Appearance falls into one of these three buckets. The first two are skill-based and very consistent for a given player, year-to-year. The third one is luck.

Take all of a player’s plate appearances, then remove the ones where they Walk - that’s good. Then remove the ones where they Strike Out - that’s bad. Everything that’s left falls to the whims of the BABIP Gods. If your heart is true and the fickle Gods find favor with you, you may post a BABIP in the .350 range... for a season. But while exit velocity and running speed do have some influence on BABIP, luck is a bigger factor. You will not sustain a .350 BABIP as your baseline.

When the BABIP luck inevitably swings in the other direction, this is where BB% and K% will be even more important. Take Mike Trout as an example: The absolute Gold Standard in MLB hitters has run BABIPs from .298 up to .383. But a typical season sees him walk a robust 18% of the time and strikeout a relatively small 20%. For nearly 40% of his Plate Appearances, Trout is almost as likely to reach base as he is to make an out. That is tremendous value, locked-in before he even puts a ball in play.

This was the problem with Grichuk and Bader. Their extremely low walk rates and very high strikeout rates meant they, by contrast, were locked into making an out in most of 40% of their PAs. Their only chance at providing value was if the BABIP Gods were very, very good to them.

As for Edman, those underlying numbers look better, but still not great. His walk rate is similarly dreadful - actually the worst of the bunch. But his strikeout rate is much, much lower. That means Edman is only locking-in a mostly bad outcome in about 22% of his PAs, and leaving a whopping 78% to the whims of BABIP.

Putting a ball in play is undeniably better than striking out. But it’s more of a dice roll than a guaranteed success. Edman looks to be a player who will have a very high percentage of his production decided by batted ball luck, so we should expect dramatic swings in production.

I’m mostly ignoring quality of contact here, but the one other thing worth keeping in mind with Tommy Edman is the massive spike in his Isolated Power in 2019. For his entire minor league career, he was a .100 ISO guy. Then last season, in both AAA and MLB, he was a .200 ISO guy.

Maybe it was just AAA and MLB both using the juiced ball. Maybe Edman - who is clearly a smart player - made an adjustment to his approach to maximize his power. Maybe it was just a one-year blip.

These are all questions for the Cardinals to keep in mind as they plan for 2020 and how much production to expect from Tommy Edman. Me personally? I think they should be cautiously optimistic. His low K% definitely puts him a tick above Grichuk and Bader, and if the team believes a change in approach led to his increase in power and that is sustainable - all the better.

But the parallels between Edman, Grichuk and Bader are too clear to ignore. They should plan to give him opportunities, and I think a Zobrist-esque Super Sub role makes a lot of sense. But they should not slot him in as Plan A at any one position, or restrict themselves from upgrading at any position he can play because they are counting on similar production from him in 2020.