As others have already explained, in this case the EV reported by MGP's CA isn't wrong, it just requires interpretation. And I have no reason to suspect the accuracy of any EVs reported for any integral number of decks. However, as a side effect of another analysis, it's worth noting that there do appear to be some errors in the EVs reported by this CA for some depleted shoes. Unfortunately, since there isn't a nice scriptable interface to his CA to allow automated "searching" for discrepancies, I only have some anecdotal examples that yield incorrect results, and those anecdotes are all what I would describe as "pathological" . For example, consider a shoe with two aces, two 6s, and a bunch of 10s (the exact number doesn't seem to matter). I suspect that the bug is in the pair split portion of the algorithm, but I don't have any more insight at this point. I'll let you know what I find.