English forum ang chicken talk so I will reply in english. I think there are plenty of gaffers here that can give you an input. The likes of sir sundowner, sir rover, sir filamfork, sir sugboslasher, and others. Observe and also talk with your fellow cockers. By asking questions you will know who the honest gaffers are.
From the book of stringking bingham 1, 2, and 3 you will learn how cheating is done when it comes to the knife. The toe ring if it is lowered from the prop toe won't cut even if the point of the tari is aligned. Other times the mananari will tie the string tight that your roosters leg will be numb. Even if the tari is well place, sometimes it will not cut because of the metal is just made of plain iron.
Hope I have given you a little pointer.