One of the most important things that you make sure that you do is look at the options available if you challenge off your opponent’s play. In this position, it is easy to just say to yourself: “Okay, well I know that’s phoney but I have a crappy rack and I get to play FUTZ for 67, annulling your opponent’s bingo, so I accept.” That would be a horrible play in this scenario. Because we know what our opponent has, by challenging off we can use that information to our advantage: we know our opponent’s entire rack. This means that we can make plays such as setups and fishes that we wouldn’t normally be able to make, since we know exactly what our opponent has, we can predict what the board will look like. In this case, we can play MUD n2 for 15 points, somewhat confident that our opponent will not block. Then we can play FUTZ o1 for over 100 points next turn.
Losing a challenge is very devastating because our opponent has a lot of information about our rack. In the case of bingos, they know our entire rack. This allows them to make setups, fishes, or even plays that look like setups (but don’t set up anything) that put us in a very awkward position. The value of challenging not only lies in the amount of points scores, but also the amount of information that we will get about our opponent’s rack and tiles. Sometimes this information is worth a substantial amount.