The year, several individuals and Charter Captains have been fishing wind-on leaders on their spinning reels as a way to solve the leader problems that can arrive with the demands of bigger fish, heavier mono/fluoro (up to 130# or more) and longer casting rods (like the OTI Tuna Sniper). About a week ago, an 80"-class Bluefin was fought for a long 4 hour 45 minutes with a wind-on that I'd built to be tested. It ended with a broken Owner hook just as the fish was about to be "stuck". (If you are interested in their report, PM me.) The key parts of the leaders I'm having tested are: a new small no-glue, no-wrap Serve and a short 12" splice that has been designed for casting distance and to withstand the high speed trips through the guides that come with spin-casting. I have had several leaders returned from the Captains using them and after examination, I can see that they are performing well. Because of the duration of the fight and the estimated size of the fish I reported above, this past weekend I got the leader back from them and have been dissecting it to see how it fared. I was interested in whether the Splice or Serve had moved, whether the Loop to Loop had worn, and whether the tag end of the mono had started to chafe the hollow Spectra. I also examined the Triple Surgeon's Loop that they had used for the mainline loop. Other than the expected, cosmetic abrasion of the Jinkai mono near the terminal tackle end from rubbing against the fish, the Splice, Serve, loops, and loop to loop were undamaged, photos below. The Triple Surgeon's knot used for the mainline loop was solid as a rock and showed no signs of slipping or fatigue. Although the results for the Serve and Splice are particular to my design implementation, the single loop to loop connection (which was squeezed to a dot) between the wind-on leader and the triple Surgeon's Loop in the mainline can stand up to a very long fight with a big fish. If you use hollow-weave as your mainline, like I do, a spliced End Loop is even stronger and thinner than the Surgeon's Loop.