Originally posted by Sophie Hughes:

Should I shuffle 16 times each round at a GP? That seems excessive and also counter-intuitive; surely if a shuffle is sufficient in one event, an equivalent shuffle should be sufficient at any event?

I think what he's saying is that, if you have a 60 card deck, you should shuffle one more time than the number of rounds in a 60 person event. If you are playing a 2000 card deck, then you may need to shuffle closer to 16 times (in line with the GP having ~2000 players and taking 15 rounds).

Originally posted by Andrew Keeler:

Originally posted by Sophie Hughes:

Should I shuffle 16 times each round at a GP? That seems excessive and also counter-intuitive; surely if a shuffle is sufficient in one event, an equivalent shuffle should be sufficient at any event?

I think what he's saying is that, if you have a 60 card deck, you should shuffle one more time than the number of rounds in a 60 person event. If you are playing a 2000 card deck, then you may need to shuffle closer to 16 times (in line with the GP having ~2000 players and taking 15 rounds).

Thank you! That made a lot more sense than what I thought I read. I am still not sure where the log(2)+1 comes in (as this is 1.3 or 1.7, depending on whether you use base 10 or base e - log 2 base 60 is less than 1!).

Base 2. ;)

2017-09-05 11:39 GMT-04:00 Sophie Hughes <

Welp, this thread has gone off the rails a bit, not to mention being “necro'd” twice already; time to wrap up.

The original post asked about a player intentionally manipulating the starting point before shuffling, believing that it gave him an advantage, and whether or not he was Cheating by doing so. That was pretty well covered by two ‘O’fficial sources (first from Mark Brown, then from me).

We've also introduced concerns about randomization and sufficient shuffling, the math behind that, and what we care about. This very topic has been argued for longer than I've been NetRep (Nov 2004), and people still seem to get hung up on minutiae - including the statistical analysis of the results after shuffling. Dominick's math is, as usual, excellent - but largely irrelevant to actual tournament procedures. (We are not going to start using scientific calculators and spreadsheets as part of deck checks!)

But that's not where Dominick was going (I think); he was explaining that there's math to show us what optimal looks like, what random looks like, and how a theoretical shuffle could end up. I hope that no one is expecting human players to even approach optimal randomization.

I also hope that everyone is expecting - nay, demanding! - that players attempt to approach optimal randomization. As Sophie said, watch them shuffle, and judge(!) whether or not they're making an honest effort to randomize, or if you instead believe that they're trying to manipulate the order (or avoid breaking the order) of certain cards.

Also, keep in mind that questionable shuffling practices of your own deck shouldn't matter, as the opponent should (Is required to, by the MTR) disrupt any manipulation you perform by shuffling themselves. The DQs I've done, and seen most often, involve shuffling the opponent's deck; on rare occasions, we've seen a player manipulate their own deck after noticing the opponent's tendency to a simple, predictable cut.

d:^D

Edited Scott Marshall (Sept. 5, 2017 11:42:02 AM)