NCAA 10-6 Extra-Base Hit
SECTION 6. a. A base hit for extra bases is credited to the batter when it is the sole reason for his safe arrival at a base beyond first. Any fairly batted ball that clears in flight an outfield fence in fair territory, even though it may be deflected by a fielder, is a home run, subject to local ground rules.
b. When, with one or more runners on base, the batter advances more than one base on a safe hit and the defensive team makes an attempt to put out a preceding runner, the scorer shall determine whether the batter made a legitimate two-base hit or three-base hit, or whether he advanced beyond first base on the fielder’s choice.
Note: Do not credit the batter with a three-base hit when a preceding runner is put out at the plate, or would have been out but for an error. Do not credit the batter with a two-base hit when a preceding runner trying to advance from first base is put out at third base, or would have been out but for an error.
c. If a batter over-runs second or third base and is tagged out trying to return, he shall be credited with the last base he touched.
Exception—If put out while oversliding second or third base, he is not credited with reaching such base.