title: Alpha Beta Searching and Transposition Tables
body: <p>I have alpha beta search working and want to implement transposition tables to make it faster. The problem I'm having is the relationship between the entries in the table and the current position being evaluated.</p>
  
  <p>The literature I've read so far says you need to store the position type, the score, and some other information. Why do you have to store the type? Can't you just use the score as long as the entry in the table from a previous search went deeper?</p>
  
  <p><a href="http://web.archive.org/web/20070822204120/www.seanet.com/~brucemo/topics/hashing.htm" rel="nofollow noreferrer">This page</a> shows some sample code to do it, but I can't figure out why the AB search returns beta when alpha>=beta. Shouldn't you be returning alpha?</p>