Just like basketball, the NCAA Baseball tournament has 64 teams with 30 conferences receiving automatic bids for their champion (Usually the tournament champion). That leaves 34 at-large teams to be selected by a committee.
RPI gives you a pretty good indicator of where you stand nationally with other teams. Right now, the Tigers sit in the lower 70's after losing Wednesday night to Middle Tennessee. At this point in the season, a bad loss hurts more than a good win helps. To be a "Bubble" team, which basically is a border-line team to get in the tournament, you would need to be in the top-60.
Another bench-mark for getting in would be the total wins. I usually think that 35 wins before going to the conference tournament is where you want to be. In 2007, we won 33, but won another three in the conference tournament.
So, what we know now is that we are sitting at 23 wins and an RPI in the lower 70's with 18 games to go. What is remaining? If Memphis can play really well down the stretch, especially in C-USA, it has a chance. Going by Warrennolan.com the Tigers have 13 games left against top-100 teams, of those 13, seven are in the top-50. The Tigers also have five games against teams outside the top-100 with four of those outside the top-200.
So with 18 games left, Memphis would have to go 12-6 to reach 35wins. If the Tigers can avoid anymore losses to teams outside the top-100, 35 wins would put us in a good situation.
With the amount of losses to teams outside the top-100 (seven), the Tigers hopes to impress a selection committee will likely hinge on what we do in conference. C-USA is a top-five conference nationally, which means a high finish can impress. If the Tigers could win 14 games in the league (eight more) it would likely mean a top-3 finish.
Again, this is all my calculated opinion based on following this kind of stuff for 16 years as a broadcaster. The reality is, you never know what really goes on behind closed-doors when the selection committee meets.