There are very few reasons that an Auction Chairperson and/or Manager would need to delete a bid for a bidder.  However, it does happen.  Here are a few examples...

     - A bidder "mis-bids" by entering in the wrong bid amount and hitting the Place Bid Button. (ie. $250 instead of $25) 

     - A bidder contacts the Auction Chairperson and/or Manager and is no longer interested in the item for whatever reason.

There are two ways to delete bids:

Bidders > Bidder Management > Click on the "Bidder Name" > Select the Bid > click delete and confirm
     OR
Items > Item Management > Click on the number that is displayed in the column "Number of bids" > Click on the "Bidder Name" > Select the Bid > click delete and confirm