If you are referring to the 2017 Ping I blade vs the TS-1, I would defer to the playability rating comparison. The i blade is 430 points placing it in the Conventional category and the TS-1 is 711 points placing it in the Super Game Improvement category. I don’t know how much you are familiar with the MPF ratings, but those numbers tell us the TS-1 is a more stable and more forgiving iron. I do not have the blade length on the Ping i blade, but the c-dimension is 1.260″ on the Ping and 1.438″ on the TS-1. This is the dimension from the hosel centerline to where the cg is located. The longer the c-dimension the higher the playability, generally. If you hit the ball really consistently and do not need the stability and forgiveness a higher playability club offers, the Ping can perform well. However, on even the slightest mishits, the performance of a design with a higher MPF rating will provide better performance. Generally larger head designs can have a higher playability, but it totally depends on the mass and dimensional characteristics of the design, not just the size. I have seen many larger midsize and larger designs not have high playability because the cg is not where it should be. I have also seen midsize and more traditional designs have a higher playability because the cg / mass and dimensional characteristics are designed well. That is why we have the MPF system for comparing irons. You can not just go by size or features. You have to go by the measurements (vertical cg, horizontal cg, rearward cg, MOI). Hope this helps.