[Rich Ives]

It's not nearly as hard as some assume.

If a batter bats out of order, only the teams may point it out. The umpires and official scorekeeper may not.

The batter who should be batting is termed the PROPER Batter; the one actually batting is an IMPROPER batter.

If one of the teams discovers an improper batter DURING THE AT BAT: The proper batter goes to the plate and assumes the count, if any, that was made by the improper batter. No other penalty.

If the improper batter completes his AB, the objecting team must object BEFORE THE NEXT PITCH OR PLAY. If the objection is not made before the next pitch or play - tough cookies - play on.

If the objection is timely and valid 1) the PROPER batter is called out; 2) any action that happened as a result of an improper batter putting the ball in play is nullified (including outs, base advances, runs scored, etc); 3) The batter who follows the PROPER batter in the order is now the proper batter.

If there is no objection made - ignore it and play on.