I am looking for an easy to use Java library for evaluating Omaha Hi/Lo hands. I want to enter two or more hands, and zero, three, four or five board cards and be given a probability for the different outcomes. A simple EV is not enough, as I intend to use it for SnG where a guarantee of a split pot is wildly different from a hand where each player has 50% chance of scooping.

Speed is always nice, but not really my first priority. That would instead be something that I can hook up to quickly and without too much hassle. I have looked at the old pokersource.jar in poker-eval, and that library fails the ease of use criteria, unfortunately. (But if there is some very clear instructions, that would be very welcome. Yes, I have tried the pokersource mailing list, but not received an answer.)

Any ideas on where to look? This is for my own private use, so basically any license is acceptable.

AFAIK, pokersrc is your only option. If you can't get the old code working then you could try and get a friend who knows C/C++ to use the JNI interface to make a DLL for you to use (it should be pretty easy as all you will need is a single function).

Juk

I'd argue that with five board cards it's not really a "probability": Roger Federer beats Nadal 6-0, 6-0, 6-0, what it's "probability" of winning?

You could say it's a probability of 1.0, but that is still a stretch

So you want basically a fast evaluator.

For preflop matchups you want to do MonteCarlo simulations and for flop and turn you want to brute force all the possibilities.

For a full board, you want to evaluate the response.

Good Hold'em evaluator evalute hundreds of millions of hands per second at the cost of some memory (60 MB or so).

A Omaha and Omaha Hi evaluator is trivial to implement from an Holdem evaluator.

A Omaha lo isn't hard.

Pokersrc as been pointed out to you, you can search this forums and you'll find lots of threads.

Porting C code to Java isn't really hard since the Java syntax is C-friendly. It's a copy/paste from most of the code.
I ported C a lib to C# and it was all about removing implicit cast to bool, replacing pointers with arrays and stuff like that. pokersrc should be a good start.

Pokersource has a java api. I don't think it's in the official release but it's in the svn repository.

Also see this link.

You can start with the Java version of Holdem Showdown by Steve Brecher.
There you have two things, one the evaluation library that has functions to evaluate omaha hands (hi and low), and then a holdem equity calculator that takes as input cards and outputs Equity.
The omaha evaluation functions will work out of the bos, if you want to calculate equity you can modify the holdem equity calculator using the omaha evaluation functions.

http://www.brecware.com/Software/software.html

Thanks! I found a .jar that I can open in Eclipse. That's about all I had the time to do so far, but it seems quite like what I was looking for, or at least a very good start.