I find that what I call "on by error" does not always agree with what the scorekeeper feels is an error....
I found this: ?
According to ATEC
ERRORS
10.13 An error shall be charged for each misplay (fumble, muff or wild throw) which prolongs the time at bat of a batter or which prolongs the life of a runner, or which permits a runner to advance one or more bases.
NOTE (1) Slow handling of the ball which does not involve mechanical misplay shall not be construed as an error.
NOTE (2) It is not necessary that the fielder touch the ball to be charged with an error. If a ground ball goes through a fielder's legs or a pop fly falls untouched and in the scorer's judgment the fielder could have handled the ball with ordinary effort, an error shall be charged.
NOTE (3) Mental mistakes or misjudgments are not to be scored as errors unless specifically covered in the rules.
(a) An error shall be charged against any fielder when he muffs a foul fly, to prolong the time at bat of a batter whether the batter subsequently reaches first base or is put out.
(b) An error shall be charged against any fielder when he catches a thrown ball or a ground ball in time to put out the batter runner and fails to tag first base or the batter runner.
(c) An error shall be charged against any fielder when he catches a thrown ball or a ground ball in time to put out any runner on a force play and fails to tag the base or the runner.
(d) (1) An error shall be charged against any fielder whose wild throw permits a runner to reach a base safely, when in the scorer's judgment a good throw would have put out the runner.
EXCEPTION: No error shall be charged under this section if the wild throw is made attempting to prevent a stolen base.
(2) An error shall be charged against any fielder whose wild throw in attempting to prevent a runner's advance permits that runner or any other runner to advance one or more bases beyond the base he would have reached had the throw not been wild.
(3) An error shall be charged against any fielder whose throw takes an unnatural bounce, or touches a base or the pitcher's plate, or touches a runner, a fielder or an umpire, thereby permitting any runner to advance.
NOTE: Apply this rule even when it appears to be an injustice to a fielder whose throw was accurate. Every base advanced by a runner must be accounted for.
(4) Charge only one error on any wild throw, regardless of the number of bases advanced by one or more runners.
(e) An error shall be charged against any fielder whose failure to stop, or try to stop, an accurately thrown ball permits a runner to advance, providing there was occasion for the throw. If such throw be made to second base, the scorer shall determine whether it was the duty of the second baseman or the shortstop to stop the ball, and an error shall be charged to the negligent player.
NOTE: If in the scorer's judgment there was no occasion for the throw, an error shall be charged to the fielder who threw the ball.
(f) When an umpire awards the batter or any runner or runners one or more bases because of interference or obstruction, charge the fielder who committed the interference or obstruction with one error, no matter how many bases the batter, or runner or runners, may be advanced.
NOTE: Do not charge an error if obstruction does not change the play in the opinion of the scorer.
10.14 No error shall be charged in the following cases:
(a) No error shall be charged against the catcher when after receiving the pitch, he makes a wild throw attempting to prevent a stolen base, unless the wild throw permits the stealing runner to advance one or more extra bases, or permits any other runner to advance one or more bases.
(b) No error shall be charged against any fielder who makes a wild throw if in the scorer's judgment the runner would not have been put out with ordinary effort by a good throw, unless such wild throw permits any runner to advance beyond the base he would have reached had the throw not been wild.
(c) No error shall be charged against any fielder when he makes a wild throw in attempting to complete a double play or triple play, unless such wild throw enables any runner to advance beyond the base he would have reached had the throw not been wild.
NOTE: When a fielder muffs a thrown ball which, if held, would have completed a double play or triple play, charge an error to the fielder who drops the ball and credit an assist to the fielder who made the throw.
(d) No error shall be charged against any fielder when, after fumbling a ground ball or dropping a fly ball, a line drive or a thrown ball, he recovers the ball in time to force out a runner at any base.
(e) No error shall be charged against any fielder who permits a foul fly to fall safe with a runner on third base before two are out, if in the scorer's judgment the fielder deliberately refuses the catch in order that the runner on third shall not score after the catch.
(f) Because the pitcher and catcher handle the ball much more than other fielders, certain misplays on pitched balls are defined in Rule 10.15 as wild pitches and passed balls. No error shall be charged when a wild pitch or passed ball is scored.
(1) No error shall be charged when the batter is awarded first base on four called balls or because he was touched by a pitched ball, or when he reaches first base as the result of a wild pitch or passed ball.
(i) When the third strike is a wild pitch, permitting the batter to reach first base, score a strikeout and a wild pitch.
(ii) When the third strike is a passed ball, permitting the batter to reach first base, score a strikeout and a passed ball.