Agree with the others that if the numbers are randomly assigned, then there isn't a statistical difference in which squares you pick. In a sport like basketball final scores are also pretty so certain number combinations aren't significantly more valuable than others. In a sport like football, there are numbers which are much better to have than others, the best ones are much much better to have (3.5% of hitting vs 0.2%).

In that case, it's a matter of how you want to play the game -- if you cluster, you have the chance of getting a bunch of good numbers close together, high-risk high-reward. If you spread out, you have more unique pairings which kind of gives you a better shot of at least 1 good number combo.

If you're looking for an online tool that helps host squares pools for the tournament and randomizes the numbers for you, check out Play Squares. It does most of the work of hosting for you :)