The following apply to the 2000 printing of Gap-Air Mirror Defense for Youth Football and not to the revised 2009 printing. They were corrected in the book for the 2009 printing.
The corners in the throwback pass diagram should have aligned on the two flankers.
The line from the C in the middle of the defense should go to the tailback, not the fullback. The M in the fullback circle is correct as to which defender covers the fullback.
Add the words or power I after the phrase four backs in a line behind the center in the cornerback alignment rule 3 (on page 14 of the current version of the book).
On page 12 of books printed before 10/27/01, the alignment rule said the middle linebacker lined up on the innermost non-tight end on the side with three or four receivers. That is incorrect. He lines up on the middle non-tight end receiver. The rule is stated correctly elsewhere in books printed before 10/27/01. The reason for this rule is that it is the simplest rule.
A couple of readers have told me at the beginning of the 2001 season their defense has been beaten by long passes. In each case, questioning revealed that what happened was that the linebackers or cornerbacks completely ignored receivers and let them go unbumped and uncovered straight down the field. The middle linebacker also ignored such receivers until it was too late.
This is the fault of the coach, not the GAM defense. You cannot just tell the defender to cover passes. You must give them many reps of doing it. Even though only about 5% of youth plays are passes, about 20% to 40% of the plays your scout practice team runs should be passes in order to maintain adequate pass consciousness in the minds of your linebackers and cornerbacks. Watch your linebackers and corners carefully during games and scrimmages to make sure they are not ignoring the receivers and focusing only on the run. Typically, they neither cover the receiver nor rush the passer. Well, if you are not going to cover the passer, which is bad, at least rush the doggone passer. About the dumbest, worst thing your defender can do is let the receiver go and stay on the line of scrimmage as some sort of spectator with a great seat.
The defender must cover the receiver. Keep increasing the percentage of pass plays in practice until you achieve the necessary level of pass consciousness on the part of the backers and corners.
Around page 30it changes as I make changes to the bookthere is a subhead Left stunt. A sentence in the second paragraph under that subhead refers to the left guard tackle. Strike the word tackle from that phrase. Its the left defensive guard. Also, one reader says they are lined up against the left offensive guard, not the right offensive guard as I say. Nope. I got that right. Remember that the offense names their positions opposite the defense. The offensive guard on the defenses left is the right offensive guard and vice versa. My early versions of the book said the defensive guard was lined up against the offensive tackle. That was incorrect. He lines up on the offensive guard as shown in the diagram, which has been correct in all printings.
Coach Keith Hopkinson of Austin wrote to point out that my alignment rules and my diagrams conflicted versus trips and quads on pages 14 and 15. He wanted to know which was correct. The answer is the rules. The diagrams are wrong. In trips, you should have a cornerback on the two outermost receivers on the trips side and a linebacker on the innermost trips receiver. In quads, the middle linebacker should cover the middle receiver of the five receivers, that is, the third one in from the outside on the quads side and a linebacker should cover the innermost quads reeciver.