Thats good advice from MST....
The pitch has to be called regardless of the batter backing out, so a reasonable zone must be established. What is reasonable?......some would tell you nose to toes and box to box.......thats always the funny line, but changing zones has never worked for me, just messes me up......
Pretty much a ball width around the zone is reasonable for all baseball......but many lower age level youth umpires call the egg zone.......imagine an egg from the shoulders to the knees.....more narrow at the top, wider lower........
I agree with MST, reluctant or fearful batters do not get a pass if they back out.....but focus on the ball not the batter. ...even at 8u, we umpire ....let the coaches coach the players...call strikes early and find the medium that has the batter swinging and the game moving. best of luck......you are going to need it.....
And dont bother with 6.02 in this case. That is for much more advanced baseball where the batter is stepping out of the box to disrupt the pitcher......call the pitch what ever it is.......