LAFAYETTE — The University of Louisiana at Lafayette baseball team is making a rare out-of-state midweek road trip to play Southern Mississippi on Tuesday, and coach Tony Robichaux says there are several good reasons for the trip.

“It’s RPI, it’s a potential regional team, it’s a regional atmosphere, it’s a tough place to play, and they draw good there,” Robichaux said.

“You add all that up, that’s good for our weathering.”

That’s either three or five reasons right off the top of Robichaux’s head, depending on whether the listener thought the last three reasons had any discernable difference.

But for the Cajuns (27-13), Robichaux might as well have stopped at reason No. 1 when discussing the importance of playing a late-season midweek road contest against Southern Miss (29-12).

It’s all about the Rating Percentage Index. More specifically, it’s all about getting that number as high as it can possibly go before the tournament selection committee decides who is going where after the conference tournaments.

Heading into Tuesday’s game, the Cajuns have the 12th-best RPI in the country, according to warrennolan.com.

The Golden Eagles have the No. 19 RPI.

That leaves open an opportunity for the Cajuns to improve their stock even further based on the way the RPI rankings work.

Twenty-five percent of a team’s RPI is based on winning percentage against Division I schools, 50 percent is based on opponents’ winning percentage, and 25 percent is based on opponents’ opponents winning percentage.

Teams can also get bonus points for road wins against top-75 RPI teams, with the amount of bonus points being broken down into three levels according to the home team’s RPI ranking. Since Southern Miss has a top-25 RPI, the Cajuns would be awarded .0024 bonus points for a win.

Conversely, a team can get penalized for losing to a bottom-75 RPI team at home.

The Cajuns have three home games remaining against a bottom-75 team in Appalachian State.

Robichaux said he goes over the importance of RPI at the beginning of every season with his team.

“We explain to them the value system so that they understand when they’re playing a bad RPI team versus a good RPI team,” Robichaux said. “We want them to understand RPI. We don’t want them to worry about it or dwell on it, but we want them to learn it so they understand that our No. 1 goal is to try to get in that 64 (team NCAA tournament) field.

“Once you get in the 64 field, if you happen to get hot, you can do some damage. If you don’t get into the 64 field, I don’t care how hot you get, you’re going to be in the backyard playing whiffle ball.”

Robichaux explained that having a high RPI insulates a team against relying on receiving an automatic bid into the NCAA tournament.

The Cajuns saw first-hand evidence of that importance when they beat South Alabama, the Sun Belt’s regular-season champion, in last year’s conference tournament title game.

The Cajuns made the NCAA tournament as a No. 3 seed thanks to Stefan Trosclair’s 12th-inning grand slam that sealed a conference tournament championship. South Alabama, which finished with the No. 78 RPI last season, did not receive an invitation to the tournament.

“We want to try to leverage ourselves to where we can protect ourselves from that happening to us in a tournament situation,” Robichaux said. “If you don’t end up with a good RPI, guess what, you’re going to (have to) win the conference tournament.

“You’ve got no backup plan, and you’ve got to be good over three days. I don’t like that.”

With that in mind, the Cajuns will send sophomore right-hander Evan Guillory (4-3, 3.10) to the mound Tuesday night in Hattiesburg. In his past three starts, all at home, Guillory has allowed just five earned runs in 23 innings.

Robichaux said he will also have his outstanding 1-2 relief punch in right-handers Eric Carter and Dylan Moore available if the Cajuns need them.

The Golden Eagles are countering with left-hander Stevie Powers (0-1, 4.29).