
## Attac-200: An Adaptive Autonomous Bidding Agent Peter Stone

Michael L. Littman AT&T Labs Research, 180 Park Avenue Florham Park, NJ 07932 USA

## Sat Inder  Sing H

Michael Kearns Syntek Capital, 423 West 55th Street New York, NY 10019 USA
P ST ONE QRE SEAR CH .ATT .COM
M LITTMAN @ RESEARCH .ATT .COM
SATINDER .BAVEJA @ SYNTEK CAPITAL .COM MICHAEL.KEARNS@SYNTEKCAPITAL.COM

## Abstract

The First Trading Agent Competition (TAC) was held from June 22nd to July 8th, 2000. TAC was designed to create a benchmark problem in the complex domain of emarketplaces and to motivate researchers to apply unique approaches to a common task. This article describes ATTac-200, the first-place finisher in TAC. ATTac-2000 uses a principled bidding strategy that includes several elements of adaptivity . In addition to the success at the competition, isolated empirical results are presented indicating the robustness and effectiveness of ATTac-2000's adaptive strategy.

## 1. Introduction

The first Trading Agent Competition TAC  was held from June    nd to July   th ganized by a group of researchers and developers led by Michael Wellman of the University of Michigan and Peter Wurman of North Carolina State University  Wellman  Wurman O Malley Bangera Lin Reeves Walsh Their goals included providing a bench mark problem in the complex and rapidly advancing domain of e marketplaces  Eisenberg and motivating researchers to apply unique approaches to a common task  A key feature of TAC is that it required autonomous bidding agents to buy and sell multiple interacting goods in auctions of different types Another key feature of TAC was that participating agents competed against each other in a preliminary round and many practice games leading up to the finals  Thus  developers changed strategies in response to each others agents in a sort of escalating arms race Leading into the competition day a wide variety of scenarios were possible A successful agent needed to be able to perform well in any of these possible circumstances This article describes ATTac-2000 the first place finisher in TAC ATTac-2000 uses a principled bidding strategy which includes several elements of adaptivity In addition to the success at the competition isolated empirical results are presented indicating the robustness and effectiveness of ATTac-2000 s adaptive strategy The remainder of the article is organized as follows Section presents the details of the TAC domain  Section  introduces ATTac-2000 including the mechanisms behind its adaptivity Section describes the competition results and the results of controlled experiments testing ATTac-200 s adaptive components  Section   compares ATTac-2000