My goal for "The Modified Optimal 2/1-Club System" is to show how to use the Optimal Point Count (OPC) method of hand evaluation developed by Patrick. Darricades in his book "Optimal Hand Evaluation" (2019) to improve the dialogue between two players to achieve an optimal bridge contract. The primary objective is to demonstrate how to apply the new system approach to contract bridge by illustrating a more accurate method of hand evaluation whether you play 2/1, Standard American (SA), Acol or Precision, among others.The Two over One (2/1) Game Force bidding system was an improvement over the SA System that has been in effect and played by bridge players for many years. Many claim that the advantage of the 2/1 system allows the partnership to know that game is possible with only a single bid provided one has 13+ points. As we shall see for suit contracts it is only true if the opening 2/1 bidder has 15 points, not 12/13 points since 25/26 points do not result in game whenever a singleton in one hand finds wasted honor points in partner s hand. Yet, most 2/1 conventions call for 13+ High Card Points (HCP). Another flaw of the 2/1 approach is the fact that opening 1-level suit bids have a wide bidding range (12-21). To eliminate this flaw, the principles of Pinpoint Precision with 1*= 18+ points andnew responses associated with a new and improved hand evaluation method. A major flaw of most Strong Club opening bids is that they are based solely on HCPs with opening bids of 1*=16/17+ HCP.To correct these flaws among others, the search for a better hand evaluation method and a better bidding system has been unrelenting. Hand evaluation methods have been popularized by Milton Work, Charles Goren, Marty Bergen, and Petkoy Zar, and others. All falling short when applied to the commonly used dialogue bidding systems.The Optimal Point Count (OPC) method of hand evaluation corrects the many flaws of prior hand evaluation methods when applied to any bidding system.In this book many traditional/standard bidding practices that do not help to show suit fi t and distribution are to be avoided or re-defined. Splinters and mini splinters which show the location of voids and singletons to help locate wasted honors, the XYZ bidding convention, cue bidding, and new bids for the investigation of game and slam are among the cornerstone conventions reviewed in this book.Newly defined 2 and 3-level bids to show hands with 6/7+card suits are defined to prevent the opponents from finding their optimal contract and to improve upon difficult bidding sequences using traditional bidding strategies. The evaluation of one s Offense to Defense Ratio (ODR), why many well-known bidding sequences must be avoided, and an analysis of several old standard bridge laws/rules are reviewed to show why they need not be used to improve one s judgement if one employs the OPC method.