In Nassim Taleb’s Triad, fragile is on the left, robust in in the middle or neutral position, and antifragile is on the right (Taleb, 2014):
Fragile -- Robust -- Antifragile
Fragile things break when exposed to stressors*.
Robust things neither break nor improve — they remain unchanged when exposed to stressors.
Antifragile things improve when exposed to stressors.
I was thinking about antifragility last night while playing poker. One of the games we played was dubbed “The Grinch” and the basic premise was players were dealt two cards face-down and a board was created with a number of cards equal to the number of players plus one (n+1). For example, we had six players, so a board of 7 cards was placed, all face up. Each player for their turn picks one of the cards from the board to build their hand. The last card left face up becomes a wild card. After betting, the dealer replaces n cards in the board, again all face up and players are again allowed to chose any card, including the previous wild card (which then becomes a normal, non-wild card) and whichever card is left in the board is the new wild.
This selection process is done repeatedly until all players have built a hand of 7 cards but each round had the possibility of a completely different wild card. Therefore the hand you are building this round, based on a given wild card, could be weaker or even become a losing hand if the wild card changes.
The wild card in this case is a stressor and for an antifragile system, stressors are sources of information; information on what other players don’t have, what other players want, etc.
The antifragile (and winning hand) in this case was one that was built with complete lack of regard for any wild card except the last one, because it was the only true wild card any previous cards in that position were only potentially wild, so long as no one picked it up. The winning hand was a four of a kind with the last wild card being the fifth and the major gamble being the strength of the hand against another 5-of-a-kind hand but since the board was always visible, one had a pretty good idea if someone else was building a strong hand, based on the cards they were taking from the board.