In transparent first price auctions, buyers will receive the second highest bid (or minimum bid to win) after the auction closes (ref https://blog.google/products/admanager/rolling-out-first-price-auctions-google-ad-manager-partners/). This information helps the buyer to refine the bidding algorithm. The second highest bid is needed in both winning and losing cases, this post will focus on the winning case. Currently Fledge supports highestScoringOtherBid and madeHighestScoringOtherBid in reportWin. madeHighestScoringOtherBid is a bool field indicating whether the winning interest group owner was the only bidder that made bids with the second highest score. These two fields are insufficient for the purpose of competition modeling. When madeHighestScoringOtherBid is true, the winning buyer has no information about the true auction competition, using highestScoringOtherBid will overestimate and create self-competition.

In addition to these two fields, we propose to add another field highestScoringOtherBidFromOtherBuyer, which is the highest scoring bid from a different interest group owner other than the winner. In the winning cases, this field will be sufficient and useful for buyers to learn about auction competition for bidding optimization.