The Kansas City Royals are changing the dimensions of the Kauffman Stadium outfield walls. By bringing in the left and right field walls about 10 feet, and lowering the wall height a foot and a half in most places, they’ll certainly make the park more home-run friendly. But what other areas of the game will the changes impact?
Only four teams hit fewer homers than the Royals last year, and only three hit fewer at home. As measured by the park factors on Baseball Savant, MLB’s statistical warehouse, Kauffman Stadium is the fourth-hardest park in baseball when it comes to hitting it out. Only the parks in Cleveland, San Francisco and Pittsburgh have been tougher on homers.
Derek Carty, who runs THE BAT X projection system, crunched the numbers to see how they might impact Royals hitters.
Projections before and after park change
NameOld SLGOld HRNew SLGNew HR
0.521
30.2
0.525
31.4
0.455
29.2
0.462
30.4
0.437
22.7
0.443
23.6
0.383
15.8
0.388
16.4
0.389
12.8
0.392
13.5
0.400
12.6
0.401
13.1
0.395
11.8
0.398
12.3
0.404
10.7
0.409
11.8
0.387
10.2
0.392
9.8
0.370
7.6
0.373
7.9
0.329
6.5
0.332
6.8
As you can see from the before and after, Royals hitters will almost certainly hit more home runs in 2026. But not that many more, maybe? The median change in projected slugging is around 4 percentage points, and regular hitters might see another homer or two.
The way projections work, this shouldn’t be too surprising. The system will look at the fact that these players play only half their games at home, that only two parts of the park are affected, and that only fly balls to those two parts of the park can potentially turn into homers.
But there’s also no impact on batting average, despite the extra homers. That’s probably because doubles are changing into homers, most often. There could even be a negative effect on batting average with the new dimensions. Moving in the fences will reduce the amount of grass that the outfielders have to cover, and Kauffman used to be one of the largest outfields in baseball.
The interesting thing about KC pulling in the fences is … Coors will become even *more* of an outlier.https://t.co/jxZv1N8Ph3 pic.twitter.com/InWKqtbRpK
— Mike Petriello (@mike_petriello) January 13, 2026
Kauffman Stadium’s old outfield size has been a huge source of one of the strangest park factors in baseball — strange at least to many of the players who’ve called it home. Overall, Kansas City plays in a park that skews very slightly hitter-friendly despite suppressing all those homers. That’s at least partially because the outfield is so big. For doubles and triples, Kaufmann is a top-five park.
Royals first baseman Vinnie Pasquantino discussed the idea that hits might go down while homers go up, and what that might mean for him and other hitters on the team in a social media post Tuesday.
Please don’t read this is you don’t care. This is too long and after I wrote it I felt dumb but I’ll still put it out there. At the end of the day our job is go win games that’s it.
I’m just going to respond like an adult.
I’m very curious how this is going to play out in… https://t.co/DFqbY7WVjt
— Vinnie Pasquantino (@VPasquantino) January 13, 2026
The team itself has modeled what it thinks will happen and has determined it’ll be a net positive for the organization overall, and that Kansas City hitters will benefit.
“During the course of the season, we just started doing some research, running some numbers and (were) trying to figure out how much this really impacts our offense,” general manager J.J. Picollo told MLB.com. “Consequently, how would it affect our pitching staff? Ultimately, we concluded that we would be a better team offensively. With our current pitching staff, the changes in the dimensions wouldn’t impact (pitching) negatively as much as it impacts our offense positively.”
Homers are worth more than doubles and triples are pretty rare these days, so the benefit to the offense makes sense. But there’s a little wrinkle as to how Kauffman plays that might lead to some ramifications on the pitching side. As a park, it seems to suppress strikeouts. Some hitters have credited the phenomenon to seeing the ball really well there, but at least one hitter had a different idea.
“The pitchers know they won’t give up homers,” Tommy Pham of PhamGraphs fame once told me, “so they live in the zone without being scared.”
There’s some evidence for that. Over the course of the 18-year history of pitch tracking, only five teams have seen their pitching staffs pitch more in the strike zone at home than the Royals have. Will Royals’ pitchers immediately change their philosophy, or will they continue to pitch in the zone and allow more home runs than the team currently expects?
Even setting that question aside, by changing the outfield dimensions, there is a modest change in pitching projections, again from Carty’s THE BAT X projection system:
Projections before and after park change
NameIPOld ERANew ERA
155
4.46
4.50
168
3.31
3.36
163
4.79
4.86
142
4.39
4.45
128
3.86
3.91
70
4.47
4.51
61
4.71
4.77
71
4.69
4.75
45
3.69
3.73
44
4.41
4.46
43
4.02
4.06
42
3.94
3.97
41
4.57
4.63
You can quibble with the actual numbers, given some of the Royals’ recent success on the mound, but the front office’s work could still be right. The new walls could make for a small but noticeable change in homers, not a big change overall for their pitchers. Nonetheless, it will be fascinating to see how these new outfield dimensions change both the park factors as well how the park is perceived by free-agent pitchers and hitters.
While the Royals have been successful as an organization in signing pitchers off the market, it’s been a tougher go on the hitting side. Seth Lugo, Michael Wacha, Will Smith, Jordan Lyles, Aroldis Chapman, Zack Greinke, Carlos Estéves and Michael Lorenzen have all signed free-agent deals with the Royals in the last four offseasons. Hitters? Hunter Renfroe, Adam Frazier, Austin Nola and Garrett Hampson are the full list. Maybe they are targeting pitchers, or maybe hitters, when offered similar deals elsewhere, have decided to play in a friendlier home park.
The Royals will join the Padres, Mariners, Giants, Orioles and others that have altered their walls to maybe make their ballpark play more neutrally. A front office executive explained to me once why they might have done so.
“If you can’t sign any one portion of the market, you’re cutting yourself off of potential value deals,” he said. “And you need to find value wherever you can.”
“All in all I truly believe hitters/pitchers alike just want fairness,” Pasquantino said in his post.
Maybe changing the walls is about changing the vibes among hitters as much as anything else.
The new dimensions at Kauffman will certainly mean more homers. But what it means for offense as a whole beyond round-trippers, the pitching staff and how they pitch, and for the front office and their pitches to free agent hitters — those will the fascinating secondary effects that may take a few years to take hold.