The CURSD model liked the Bruins on Sunday night. The scoreboard did not.
Boston finished the night on the wrong end of a 4-3 result in Buffalo, and a -0.90 luck delta in the CURSD single-game index, one of the widest deserved-better swings the system has logged in this first round. The Sabres got the win. The Bruins got the underlying numbers. In a seven-game series, only one of those two things counts.
The shape of the game was familiar to anyone who has watched Boston in 2026: a team that controls long stretches of play, generates the higher-quality chances, and then watches a goaltender at the other end have the evening of his life. Buffalo was outshot and out-chanced through two periods, gave up the better looks at even strength, and still led after forty minutes. Every Sabres goal felt like it came from a different zip code than the run of play.
That is how one-goal playoff losses usually feel. It does not make them any less expensive.
Boston's power play, a season-long point of stress, picked the wrong night to go one for four. Three minutes of clean zone time on the second unit in the third period produced four shot attempts, one shot on goal, and zero goals. The Bruins' fourth line, meanwhile, outplayed its matchup for most of the night and finished without a point to show for it. The extreme single-game luck swing CURSD flagged was not a statistical artifact. It was a sixty-minute pattern.
The playoff context is what makes the -0.90 delta sting. Regular season regression eventually pays you back. A series does not care. Boston is now down 1-0 with home ice lost, having played well enough to be up 1-0 with home ice held. The math of a best-of-seven is unforgiving: a team that loses the game it deserved to win has to turn around and win one it probably should have lost, just to break even.
The Bruins will take the process. They will point to the shot share, the expected goals, the quality of looks, the way they tilted the ice in the second period. All of it is real. All of it is in the CURSD signal.
None of it is in the series score.
Game 2 is Tuesday. The underlying numbers say Boston should win it. The underlying numbers also said that about Game 1.