1819 Half Dollars can be found with a so-called normal date or as an 1819/8 overdate. The overdate varieties come in two distinct types: Small 9 and Large 9. In reality, the size difference is very slight. Actually, it is easier to tell the two types apart by the overdate itself. On the Small 9, the overdate is very clear and there are enough remnants of the underlying 8 to make an "eyeball" attribution. On the Large 9, the overdate is much less distinct and it appears primarily as a joining of the lower loop and the ball of the 9.
Five different die varieties comprise the Large 9 overdate (plus two recognized die states). Three of the varieties are common, one is rare, and the two die states are very scarce to very rare, thus it is worth going through the process of identifying the dies.
The Condition Census for the Large 9 Overdate runs from MS64 to MS66.