Grunching:
Balks in OBR (which also applies to LL games on 90' diamond and PONY, but I am not familiar with CCA or FED interps)
Obviously all situations with runners on
From the wind up:
the pitcher is in contact with the rubber with both feet, facing the batter. from here he can do 3 things:
1) step towards a base and throw to it so long as either a) it has a runner on it or he is making a play at the that base (such as an appeal or a runner has made a break for that base, although not in the case of a runner faking with a stutter step)
2) begin his pitching motion, any movement that is not stepping to a base in part 1 and is also not part 3 is considered to begin the pitching motion, he cannnot stop, he cannot change his mind and take a new sign, once this begins, he must end up going to the plate with a pitch
3) step on the rubber, with his pivot. this cannot occur if any other motion has already started. once he steps on the rubber backwards (towards 2B) he is an infielder.
From the stretch: one foot in contact with the rubber (pivot foot)
Pre-set, that is before the pitcher brings his hands together and STOPS (more on this later), he has some flexibility, he can look around to the bases including turning his body, his arms can dangle or remain in place, he can even make a momentary adjustment of the ball with both hands (that is, bring his hands together to change his grip or the position of the ball in the glove). if this is, in the umpires judgment, more than a momentary adjustment, it is a balk.
he cannot start to come set then stop. this is the most common balk at the MLB level usually in the form of a flinch or standing up slightly from peering into the catcher then going back down to get another sign; this is a balk.
in order to deliver the pitch, he must first come to a complete, discernible stop in the set postion, that is hands together not above the head. a complete stop is just that, a complete stop, not a "pause" or "delay," although it does not have a set time limit. as the famous quote goes "you'll know it when you see it." discernible is in the umpires judgment, he could tell (discern) there was a complete stop. once he is in this set position, he can no longer move anything below the neck that doesn't start one of the following three options:
in either the set or the pre-set position the pitcher can do the same 3 things:
1) step to a base additional caveat: if the free foot crosses the back plane of the rubber, the pitcher cannot step towards first or third, he can only continue to second or complete the pitch to the batter
2) deliver a pitcher
3) step of the back of the rubber and become an infielder
all three have the same caveats as in the wind up
good step or bad step?
a step must have two things, distance and direction. distance means it must move CLOSER to the base than it started. direction means it must be MORE towards the base and any other base. with the 45 foot line/degree examples, yes anything from that angle (which is a line from the pitcher to the 45 foot line) towards first base is a legal step to first.
"special" moves
first base - you have to through to it
fake to third, throw to first - in order to be legal two things must happen/be true. There must runners on at least 1st and 3rd base, the pitcher's pivot foot must disengage the rubber before he turns and throws to first
jump/spin move - this is considered a move from the rubber (important for base awards on over through) which means that the free foot must still make a good step, gaining distance and direction towards the target base and must be complete before releasing the ball (he cannot throw the ball in mid air, then land with a good step - this is a balk)
charlie hough move - this is a slow motion spin move by a right handed pitcher to first base. the pivot foot moves towards third base slightly, usually turning counter clockwise, then the free foot steps to first and throws. this never retires the runner and is not a balk because umpires felt bad for old charlie.
throwing to fielders not on the base - if not part of an attempted play to retire a runner, this is a balk.
pitcher drops the ball while in contact with the rubber and it does not cross either foul line - balk
on deceiving the runner: a little knowledge is a very dangerous thing. deceiving the runner is a balk! not true. if a pitcher makes a motion resembling his pitching motion, while not in contact with the rubber, in an attempt to deceive the runner, this is a balk. the pitcher's job is to deceive the runner, so don't go balking pitchers for 'deception!'
going to mouth in the circle is always a B-A-L-L never a B-A-L-K
if a pitcher goes to the mouth anywhere and doesn't wipe, you change the ball and warn him, if he does it again you run him
how to enforce balk - not immediately time, if the pitch occurs and all runners (including the batter-runner on a struck ball, dropped 3rd strike, HBP, ball 4 or any other situation where batter becomes batter runner) advance AT LEAST 1 base, the result of the play stands.(if a runner or batter/runner misses a base, he is said to have advanced to that missed base for the purposes of this interp)
in ALL OTHER SITUATIONS, pitch is neglected, time is called, all runners advance 1 base. there is no option play on a balk like catcher's interference, even if the result of the play is detrimental to the offensive team.
i will not get into the philosophical discussions of tailoring balk guidelines/strictness to age groups.
hope this helps, quick scan saw no typos, but if there are feel to mention and i'll edit.