(This story first appeared in Tuesday’s USA TODAY.)

The moment UFC heavyweight Ben Rothwell set foot inside the cage in Connecticut earlier this month, he knew something was different.

At first, he thought it was all in his head. He suddenly felt more comfortable in the UFC’s octagon, more at home. Perhaps, he told himself, he was finally getting used to his surroundings after nearly five years and six fights with the organization.

“I noticed right when I stepped in,” says Rothwell (34-9 MMA, 4-3 UFC), who scored a first-round TKO victory over former Strikeforce heavyweight champ Alistair Overeem at “UFC Fight Night: Jacare vs. Mousasi” that night. “I didn’t know it was that (the cage) was smaller. They told me after.”

At first it sounds like a minor difference. The UFC’s full-sized cage – the one it typically uses for major pay-per-view events in places like MGM Grand Garden Arena in Las Vegas – measures 30 feet across. The smaller cage that it reserves for more intimate venues, like at Foxwoods Resort Casino in Ledyard, Conn., is 25 feet in diameter.

But do the math on the total square footage and you have one cage that’s 44 percent larger and 20 percent wider, says statistician Reed Kuhn, who has analyzed the effect of cage size for his blog, Fightnomics.com, and found that fights in the smaller cage are notably more likely to end in a knockout or submission, in part because fighters throw around 20 percent more strikes than in the larger cage.

“It’s not anything magical, just that there’s more engagement in a smaller cage ,” says Kuhn, who also devoted a chapter his “Fightnomics” book to the topic of cage size. “It’s silly to think there wouldn’t be an effect. Imagine shrinking a baseball field by 44 percent. You’re going to have way more home runs. Imagine doing the same thing to a hockey rink. It’s going to change how the game is played.”

Whether that change is for the better depends on who you ask. UFC heavyweight Matt Mitrione, who also scored a knockout win at the same event, made it clear at the post-fight news conference that he is not a fan of the smaller work space, especially for heavyweight bouts.

“I don’t like fighting in that small cage,” Mitrione (8-3 MMA, 8-3 UFC) told reporters. “I’d rather fight in a field than a phone booth. We’re big bodies. You take two steps and you’re fighting in the middle of it. For me, mobility’s a big part of my game – that, and being athletic. For me, it feels like every time I make a movement I’m a foot and a half from one side of the cage or the other, so it’s more difficult.”

For other fighters, like UFC middleweight Tim Kennedy (18-4 MMA, 3-0 UFC), the small cage is actually preferable, he says. After knocking out Rafael Natal in November 2013 at a UFC “Fight for the Troops” event that utilized the smaller cage due to space restrictions in the venue at Fort Campbell, Ky., Kennedy says he lobbied the UFC to use the small cage again for his next fight against Michael Bisping this past April.

“That didn’t happen, and I ended up having to chase him around a lot more,” says Kennedy, who would go on to win that fight by unanimous decision. “I feel like the smaller the cage, the more finishes you usually see. And fights that end in a finish, I usually win those – so that’s good for me.”

The problem, according to several fighters, is that the UFC doesn’t always tell them beforehand which cage it will use. According to Mitrione, his first questions when the UFC offers him a fight now are all about venue and cage size.

“That last few times I thought it was going to be a full-sized cage and I come in to find out it’s not, it’s a 25-footer,” Mitrione said in Connecticut. “It makes a difference for me, mentality-wise.”

According to UFC officials, the organization does not “proactively” reach out to fighters to tell them which cage they’ll be fighting in. In past years the 25-foot octagon might have only come out for “The Ultimate Fighter” finale events, such as the ones that took place in the cramped Pearl at The Palms venue in Las Vegas. But as the UFC’s expanded schedule takes it to new venues of all sizes both in the United States and abroad, fighters say it’s often difficult to be sure which cage they’ll see until they show up for the event.

Then again, according to lightweight Michael Chiesa (11-2 MMA, 4-2 UFC), who says his cage size preference depends on his game plan, “You should automatically have an idea what size the cage is by what venue you’re fighting at. … If you think you’ll be in a big cage fighting at a small venue, you should have more common sense.”

(Pictured: Ben Rothwell)