Being a bit of a baseball fan (Blue Jays of course) I have often wondered what a bb stats db looks like. I mean, I think the game announcers can tell you what a player's batting average is when facing lefties who use brown gloves on a Tuesday with 2 men on and 2 out when player B is in the lineup in the cleanup spot but only in OPCY stadium and between July 1 1995 until now. Or some such things. What they can tell you about a situation is just nuts.
Have to wonder why you want to default a text field to zero. IMO nulls are fine, especially since you can't sum on such a field anyway, so numbers don't seem relevant - especially for a text value of RHP or LHP. I also wonder if RHP an attribute of the pitch or the pitcher. If the latter, what will you do when he's both? Depending on that, maybe this is one table (2 at most) but not 3. Excel spreadsheets as Access tables is often a sign that the db lacks some normalization.
EDIT - then again, maybe I misunderstood and the zero is for a field in the totals table.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.