Is just it me, or is anybody else worried about Duncan Keith? Maybe it’s just the recency bias of a bad three-game trip to California in which the Blackhawks defense was exposed as if each unit has to take a turn looking awful in this season that refuses to end. Or maybe Keith is the last of the core players to succumb this season to the fall of the dynasty. Or maybe it’s long-lasting and irretrievable. The last possibility is the scary one because Keith has always been the barometer of good Hawks and bad Hawks. The Hawks’ offense has always started with the defense, and the defense starts with Keith, and unfortunately of late, the defense has been inept and inert, not to mention soft and slow. In Sunday’s loss in Anaheim, Keith aided and abetted a power-play goal by Ducks forward Rickard Rakell by doing little to prevent it. In the previous game, Keith committed two awful giveaways that led to Kings goals. In the first game of the jaunt in San Jose, Keith was on the ice for four goals against while skating five-on-five. Today’s edition of Sesame Street hockey is brought to you by the letters P and U. Only six times in the last 14 games when skating five-on-five has Keith been above 50 percent in the Fenwick metric that counts only unblocked shots, according to NaturalStatTrick.com. The raw numbers in those games show he has been on the ice for three goals for and 19 against at even-strength for a minus-16. Now, plus-minus in isolation is an outdated way to evaluate players, but something that extreme is hard for me to ignore. It might not always be his fault, but he’s not doing enough to make it better. By comparison, Keith’s five-on-five Fenwick metric was over 50 percent 10 times in the 20 games before the last four weeks. His raw numbers were 17 goals for and 12 against.