This market refers to the tennis match between Karen Khachanov and Alexander Blockx in the US Open ATP, originally scheduled for September 9, 2026 at 11:30AM ET. If the match is played to completion, this market will resolve to "Over" if the total number of sets played equals or exceeds 4, and to "Under" otherwise. A set counts as played once it has begun, even if it is not played to completion. A super tie breaker is considered as one (1) set. If the match is postponed or suspended, this market will remain open until the match has been completed. A postponement alone will not trigger a 50-50 resolution. If a player retires, withdraws, is defaulted, or is disqualified, or the match otherwise begins but is not completed, this market will resolve based on any outcome that was already unequivocally determined at the time play stopped. An outcome is considered determined if it would have been guaranteed had the match been played to completion using the minimum number of additional sets required. For example, for a line of 2.5, if play stops with the players at one set each, completing the match would have required at least one additional set, resulting in at least 3 sets played, so "Over" would resolve as the winning outcome. If neither outcome was already determined at the time play stopped, this market will resolve 50-50. If the match is canceled, or has not been completed by September 23, 2026, 11:59 PM ET, this market will resolve 50-50, unless an outcome was already unequivocally determined as described above. The primary resolution source for this market will be official Grand Slam statistics; however, a consensus of credible reporting may also be used.