I’ve watched more than 1,000 baseball games in my life & still have no idea why a balk is called half the time. I saw one the other day with runners at 1st & 3rd. The runner at 1st immediately pointed at the pitcher & everyone started celebrating. They reshowed it 3 times & I have no idea why it was a balk.
If you make any type of motion toward 1st base that resembles trying to throw over you have to take your foot of the rubber first.
You have to for any type of motion that isn't going to home plate. I watched a game the other day when the pitcher had a slight spasm with his lead leg, foot even stayed on the ground, didn't even move, just a slight bobble with his knee and thigh and he was called for a balk and no one complained a single bit.
Yeah in that scenario it was probably considered he started with his windup, but didn't finish and throw the pitch. If he would have faked to 2nd or 3rd during that it would have been fine since you don't have to take your foot off the rubber to fake to 2nd or 3rd, only to 1st.
"The pitcher may throw from the rubber to a base from the windup position. (It must be done before any movement that is part of the normal motion that is part of his windup.)
The pitcher may fake a throw to second or third base from the rubber, but not to first base. This may be done from the windup or the set position. (You do not have to step off the rubber to fake to 2nd or 3rd. Only if you fake to 1st.)"
http://www.orwua.com/HELPFUL.HINTS/THEBALKREFERENCE.htm