Some people track the passing of time through watching their children. Other people track the passing of time by looking at what time it is, and comparing that to a previous time, from back in the past. I tend to track the passing of time by thinking in baseball terms. I can’t really help it, and sometimes it takes me by surprise. It feels like just yesterday that Billy Hamilton was one of the most exciting and polarizing prospects in the sport. Now Hamilton is the subject of some trade rumors, because he’s entering his arbitration years and the Reds aren’t going to be good any time soon. Life comes at you fast. (Faster than Billy Hamilton!) (But not actually that fast.)

I don’t need to explain Hamilton to anybody. At least, not anybody on FanGraphs. Runs fast, doesn’t hit. It feels like a somewhat typical profile. Maybe thinking about Hamilton causes you to think about Willy Taveras. We’ve all seen players kind of like this. I’d like to demonstrate that Hamilton is particularly extreme. While Hamilton has maybe disappointed a few observers, he’s been his own sort of player.

You’re familiar with our baserunning metric, and because of that familiarity, you know that Hamilton excels in it. Two years in a row now, he’s easily cleared a full win of positive offensive value just with his legs. To put it another way, last season, Hamilton finished with a 78 wRC+. With the bat, he was 12 runs worse than average. Offensively, though, he was precisely league-average, because of what the running did for him. The baserunning success is the obvious part, the predictable part, but I want to show you another measure. A simpler measure! Baseball-Reference tracks run-scored rate, which is basically just runs per opportunity, expressed as a percentage. No, it’s of course not perfect, but it gets at the heart of why baserunning matters. Here are the highest rates for regulars or semi-regulars since 2013, the year Hamilton first came up:

Runs Per Opportunity
Player Run%
Billy Hamilton 43%
Eric Young 42%
Rajai Davis 40%
Chris Young 40%
Ian Kinsler 40%
Dee Gordon 39%
A.J. Pollock 39%
Jackie Bradley Jr. 39%
Ender Inciarte 38%
Jose Reyes 38%
SOURCE: Baseball-Reference
Since 2013, when Hamilton debuted. I used a minimum of 1,000 total plate appearances.

A stat like this is going to have some noise, since, for one thing, it doesn’t account for the following hitters. Still, Hamilton’s first, and he deserves to be there. He’s first out of 299 players, and the average has come in at 29%. It’s worth noting that Hamilton’s first full season was his worst one on the bases, and he’s gotten even better since. Just for the sake of your own curiosity, Adam Dunn comes in last, at 17%. Tyler Flowers shows up at 19%, and then David Ortiz is at 20%. The stat isn’t very surprising, but it shows you why baserunning is valuable.

Now, moving on, many people recognize that Hamilton is great on the bases. Many people recognize that Hamilton is not great at the plate. Fewer people recognize that Hamilton has been defensively elite in center field. That’s what makes him more than just a skilled pinch-runner — he compares well in the field to just about anyone. It’s something we probably should’ve expected, given Hamilton’s footspeed and instantaneous reaction time. I got to wondering, how many players have had this sort of profile? I went to Baseball-Reference and looked at all the players with at least 1,000 plate appearances through age 25. I used a cutoff of 1961 because Baseball-Reference made that easy.

For every player, I focused on three numbers: batting value, baserunning value, and defensive value (including position). I expressed all those numbers on a per-600-PA basis, for consistency. In terms of batting, Hamilton ranks in the sixth percentile within the pool. In defensive value, he ranks in the 95th percentile. In baserunning value, he ranks in the very tippy-top percentile. I know old defensive numbers aren’t great, but it’s the best I could do. And I used Baseball-Reference’s baserunning numbers because they’re complete throughout recent history.

From there, it was a matter of finding similar players. So for the three stat categories, I calculated the standard deviations, and then I figured out z-score differences from Hamilton’s performance. Adding up the absolute values of those three z-scores yielded an overall similarity score. The lower the score, the more similar the player. Here’s the top 10, with Hamilton included for reference:

Top Hamilton Comps
Player Sim Score
Billy Hamilton 0.0
Julio Cruz 1.5
Omar Moreno 2.3
Ozzie Smith 2.4
Willy Taveras 2.5
Milt Cuyler 2.8
Josh Barfield 2.9
Julian Javier 2.9
Carlos Gomez 3.0
Devon White 3.0
Cristian Guzman 3.0
SOURCE: Baseball-Reference
Through age 25, minimum 1,000 plate appearances. Sim score based on batting, running, and fielding value. Went back to 1961 because that was a convenient Play Index cutoff.

On its own, this doesn’t tell you very much. You’ve never seen these sim scores before, so you don’t know what they mean. All you see here is that Hamilton’s closest comp is a young Julio Cruz. But now look at that 1.5 sim score. What’s the significance of that? For reference, I compared Hamilton to Josh Reddick. I didn’t choose Reddick for any great reason, but he had an unremarkable, ordinary beginning, and I just happened to see his name in the spreadsheet while scrolling. So I did all the same math with Reddick as the comparison point instead of Hamilton. The most similar young player is Howie Kendrick, with a sim score of 0.3. Then there’s Robin Yount, also at 0.3. Cruz is closest to Hamilton, with a sim score of 1.5. There are 84 players with a lower sim score when compared to Reddick. And then, Omar Moreno is second-closest to Hamilton, with a sim score of 2.3. There are 250 players with a lower sim score when compared to Reddick.

This should make it clear that Hamilton is almost unprecedented. He’s taken a familiar profile, but he’s turned all of the traits up to 11. To go in a different way, Mike Trout has been super extreme, right? By the same method, his closest comp is Alex Rodriguez, with a sim score of 1.6. That’s a little greater than the difference between Hamilton and Cruz. But then, Hamilton has four players with a sim score no greater than 2.5. Trout has nine. Hamilton has been at least as exceptional as Trout, and possibly more so. He’s clearly not better than Trout, and he never will be, but he’s one of the most unusual players in the world.

That makes him exciting and a little bit risky. If you’re another team, you might not trust Hamilton’s legs to keep up. You might not see the running or the fielding as sustainable. It’s abundantly clear that Hamilton will never be much of a threat in the box. But then, between 23 – 25, Julio Cruz was worth about 7 WAR. Between 26 – 28, he was worth about 7 WAR. He didn’t really change; he stayed the same, and Hamilton shouldn’t be approaching any physical cliff. The intrigue is his extremity, and if you believe in it, he’s a quality everyday player. He’s a weird one, but weird is no antonym of important.

People grow tired of everything. I don’t know what was expected of Billy Hamilton, and freaks never live up to the highest of expectations. Billy Hamilton isn’t invincible on the bases, and he hasn’t progressed as hoped at the plate. But, quietly, he’s remained a total freak. Hamilton has panned out, in that he is an exceptional and extraordinary major-league baseball player. The normal ones are fine. The normal ones are boring. There is no excuse for being bored by Billy Hamilton, no matter where he’s playing his game. As a Red or as something else, he should go on to be nothing but completely himself.