On the 22nd Oswald missed his target(Kennedy's head) with his first two shots and the third shot was very nearly a miss, hitting Kennedy at the upper end of Kennedy's head in the cowlick, so Oswald wasn't exactly a good shot. A professional assassin would hit a relatively slow moving target on his first shot.
According to the current version of the SBT, the first shot missed the entire car.
However, not only is there no clear evidence that the first, or any, shot missed missed, there is abundant clear evidence that the first shot struck JFK in the back and traversed his neck. There is also evidence that the second shot struck JBC. The preponderence of evidence is that the second shot was closer to the third. There is also evidence from George Hickey, that the second shot just passed to the right side of JFK's head as he saw JFK's hair on the right side lift at the same time that the second shout sounded. And there is abundant evidence that the head shot was the third and last shot.
So, according to the evidence, Oswald was pretty accurate on all three shots.