Jaquiski Tartt is one of the most underappreciated players on a great 49ers defense. He doesn't make lots of huge plays, so you don't always notice him. And he doesn't always play -- he often gets injured.
But when Tartt does play, the 49ers defense performs much better than what he doesn't. So he must do something right.
Let's examine Tartt's biggest strengths and weaknesses at this stage of his career.
Strength No. 1: Contact courage
Tartt became the 49ers starting strong safety in 2017. He replaced Eric Reid, who was terrific as a rookie, but suffered a series of concussions and started making "business decisions." Meaning he started protecting his body rather than exposing it to big hits and potential injury.
Tartt does not make business decisions. He hits hard. He uses his body like a torpedo. More on this below.
Strength No. 2: Athleticism
Lots of bad football players are courageous. Tartt is courageous and athletic, which is a nice combination for a safety. He's much more athletic than Reid.
Tartt is so fast, he can chase down Kyler Murray when the young quarterback scrambles. Not many defensive players are quick and fast enough to corral Murray.
Tartt also can cover almost any running back, including Vikings running back Dalvin Cook. Tartt shut him down in the playoffs.
Strength No. 3: Angles to the ball
Tartt primarily is a strong safety, but he played free safety in college and occasionally plays in the deep middle of the field for the 49ers. And even from that position, he takes phenomenal angles to the ball. He's like a heat-seeking missile. Rarely has to adjust his course.
Weakness No. 1: Finding the ball
Tartt has intercepted only three passes during his five-season career, because he doesn't always know where the ball is when the play starts. He often gets fooled by play-action fakes. Either he stares at the quarterback when the running back has the ball, who he chases the running back when the quarterback has it. Tartt has made these mistakes since his rookie season.
Weakness No. 2: Tackling technique
Remember when we discussed Tartt's contact courage? It's usually a good thing, but it can be a bad thing if he throws his body around wildly and doesn't use proper tackling technique to wrap up the ball carrier.
Tartt tends to propel himself shoulder-first at players' legs. That's how he broke his ribs Week 13 against the Ravens -- he dove into Mark Ingram's legs, then missed the next four games.
In 2017, Tartt broke his forearm when dove into the legs of a Cardinals receiver. Tartt missed the final seven games of the season.
Tartt has missed 40 percent of the 49ers' games since he became a starter in 2017. He will continue to miss games and break bones until he learns to wrap up consistently, which he can learn to do this offseason.
Meaning Tartt can get even better if he wants to.