What To Expect From Billy Butler?

The biggest highlight of this off-season for the Royals was signing Billy Butler to a four-year deal with a club option for a fifth year. The combination of Butler’s precocious hitting over the last two seasons and the knowledge that the Royals will control him during what could be his prime years of age 25—29 has naturally lead to much speculation about what kind of damage Bam Bam might do with the bat in the coming years. (How has “Bam Bam” not caught on more as a nickname?) Immediately after Butler signed the contract, several excellent, stats-based projection posts went up on the interwebs, all taking a different angle:

• Jeff Parker at Royally Speaking broke down hitters who had an OPS+ of 115—120 between ages 21—24 (Billy being at 118) and how they performed between ages 25—29. As Parker wrote in the title of his post, Royals fans will like some of the comparables and will not like others: he found a range from Carlos Baerga—92 OPS+ from 25—29—all the way up to Carl Yastrzemski who smashed at a 154 OPS+ clip from 25—29.
• Matt Klaassen at Fangraphs took a look at Butler’s “Future Power” potential. Some observers knock Butler for not hitting enough round-trippers, while others predict that his propensity for hitting doubles indicates a possible home run surge as he moves into his prime years. Klaassen took a look at Butler’s similar hitters via Baseball-Reference and ZiPS, and found that Billy still may be a couple of years away from a power spike, if one is to come.
• Scott McKinney at Royals Review went deep down the rabbit hole, projecting Butler’s future value compared to the cost of his contract to the Royals. The main takeaway for me is that even if Butler does not improve significantly and shifts to a full-time DH, this still looks like a great contract for the Royals (especially good news with 1B prospect Eric Hosmer waiting in the wings).

So in the interest of being both untimely and redundant, I would like to throw my hat in the ring with a slightly different angle to project what could be expected of Billy in the coming five seasons. Like Klaassen, I’m going to use the list of ten most similar batters to Butler through age 24 as found on Baseball-Reference, but look at a wide range of hitting numbers. You can click here for the full explanations of the similarity scores developed by Bill James, but these are the stats taken into account: games played, at bats, runs, hits, doubles, triples, home runs, RBI, walks, strikeouts, batting average and slugging percentage. (It drives me crazy that RBI is used as a criteria but OBP is not…c‘est la vie.) There is also a positional adjustment, so players who spent their early years playing first base like Butler will rate higher. Here are Billy’s comparables through age 24:

1. John Olerud
2. Kent Hrbek
3. Nick Markakis
4. Chet Lemon
5. Carlos May
6. Delmon Young
7. Carl Yastrzemski
8. Ellis Valentine
9. Tony Horton
10. Keith Hernandez

Just as Parker found, there are examples here to inspire both concern and optimism. The absolute worst case is the sad story of Tony Horton, who played his age 25 season in misery before attempting suicide and never returning to the game. Only considering play on the field, Carlos May probably represents the worst case: After what must have looked like a break-out age 24 year, May was a pedestrian hitter for the next five years. On the other end of the spectrum is the one Hall-of Famer on the list, Yastrzemski, he of the 154 OPS+ between ages 25—29. I think it is safe to expect Billy to fall somewhere in between those two extremes. To find a middle-of-the-road baseline of what we might expect from Billy, I averaged the age 25—29 seasons of the above players (Markakis is the same age and does not enter into the averages, and some players, like Horton and Delmon Young, do not enter into the later years). Here is what those players averaged by season, with Billy’s actual numbers to date shown at the top of the chart:

The numbers look a little low compared to what most expect of Billy, which serves as a good reminder that Butler may experience some dreaded “regression to the mean.” But it is reasonable to expect Butler to outperform those numbers, partly because he has already matched or outperformed them over the last two seasons, and because just watching the guy tells you he has the ability to keep raking for a long time to come.

The trend in the power numbers echoes what Klaassen found: Butler’s power might see a bump when he is 27—29, which correlate to the 2013—15 seasons—hopefully the same years the current crop of heralded prospects are turning into beasts. Makes that club option for his age 29 year look that much better.

Looking to the past shows that near-Yastrzemski-like numbers are unlikely, though it is encouraging that a hitter like Yastrzemski is even a part of the conversation. It is also exciting that Olerud, the most comparable hitter through age 24, hit .304/.407/.481 between ages 25—29. But averaging the performance of a larger sampling of comparable hitters serves as a note of caution. Royals fans with grand expectations may want to temper them a bit. It also shows observers should be patient with Butler over the next two years if he is not living up to lofty expectations—his best years during this contract could be the last three.