Alfonso is playing in a sealed GPT. He sits down for game 1 of his match, grabs a pile of roughly 40 sleeved cards out of his deck box, shuffles, and presents to his opponent. Upon drawing his opening hand, he immediately calls a judge and explains that this is his sideboard. He has several other packages sleeved for quick sideboarding, and he just grabbed the wrong pile from his deck box.

What do you do?

Judges, feel free to discuss this scenario on Judge Apps!

[expand title=Answer]Fundamentally what has happened here is that Alfonso has presented a set of cards that do not match the 40 cards registered as his main deck. That means we are looking at a Deck/Decklist Problem. Ordinarily, errors with a deck result in a Game Loss. However, we have a particular condition under which this is not the case:

IPG 3.4 – Additional Remedy:

If a player, before taking any game actions, discovers a deck problem and calls a judge at that point, the Head Judge may downgrade the penalty, fix the deck, and allow the player to redraw the hand with one fewer card. The player may continue to take further mulligans if he or she desires.

Typically this error is the result of failing to replace a small number sideboard cards from the prior match with their correct main deck slots. However, the IPG does not limit our ability to apply this fix based on the scale of the error. In this case, Alfonso has presented approximately 35 mismatched cards, which made it extremely easy to detect and report the error. Because he has done so, the Additional Remedy should be invoked. A Warning will be issued, and Alfonso will have the opportunity to correct his deck back to the proper game 1 configuration. After he has done so and presented the deck to his opponent, he will draw a hand of six cards and may mulligan from there.

Some discussion has revolved around how best to have Alfonso restore his deck to match his list. The answer is to simply ask him to do so. After he has, browse quickly through the deck, looking at the colors he is playing and any cards you feel are notable, either for being especially good in some matchups or rarity or any other criterion than strikes your fancy. Once the players have begun play, quickly check the player’s list to ensure that the colors and cards you mentally noted match up. Do not perform a full deck check or other intensive deck verification procedures. Alfonso has called a judge on himself after noticing an error, and your priority should be to get him playing Magic with the minimum required extension.
[/expand]