The H-O-R-S-E Challenge details. When: The quarterfinals are Sunday (7 p.m. ET, ESPN), with the semifinals and finals on Thursday (9 p.m. ET, ESPN). Rules: A coin toss at the start of each game will determine who shoots first, with the more senior player calling heads or tails. Players must describe each shot attempt, specifying the type of score they intend to make before taking a shot, such as a bank shot or swish. Dunking is prohibited. The first player in each game to accumulate the letters “H-O-R-S-E” after failing to match five shots is eliminated.