I say that purely from the simplest point of view. Have you ever noticed that if there is a shove and a call and the board is sitting a certain way, it never just misses. Where is the off suited 4 when you've got two pair vs. a flush or broadway draw? It never happens online. It's like the software is "focused," for lack of a better word, on the values of the deck there are being played.
For example, board read Kh-Tc-6s-9c. Hero is all in holding T9suited. Villain calls with JToff. 10 outs. 4 Qs, 3 Js, 3 Ks. Now, almost without question one of the following things will occur.
1. MOST often, the board will pair. The six pairs, they chop. The 9 or T pair, Hero improves to a useless boat, the K pairs, the villain wins. Despite the overwhelming odds against it, the board will pair in this scenario more than any other result.
2. A Q falls. This happens very frequently despite it being a statistical unlikelihood.
3. An A falls. Almost without question, an Ace will be the "blank" that completes this board more than any other card, and I would go so far as to say that the odds of an A hitting the river are about the same as all the other blanks combined.
4. The J falls. THIS, for some reason, does not seem to occur that often. Computer software does not tend to give a higher two pair on the river very often unless pairing the board is involved. I'm not sure why that is. But the T or Q are far more likely to hit than the J.
5. A "blank" hits. Where are all the 2, 3, 4, 5, 7, 8? There should be FAR more of them than the other cards. 24 to be exact. Including the A, there are 28 blanks in the deck, 10 outs, 3 boat makers, 2 choppers and the 9 cards in play.
Factoring in the likelihood that a higher percentage of the blank cards were folded, I would expect there to be about a 50/50 chance of a blank hitting. Yet, it's not even close to being the case. I would venture to guess that the odds of a blank hitting that river would be around 20-25%. And around 16-20% for all non-Aces.