First let me start in saying freak luck means nothing. I'm a firm believer in consistency over many multiple occurrences being the only real consideration.
That being said I started building calls just last year. I've messed around with reeds, cuts, colors, tension, etc
Youth day was a week ago. Only bird we got to answer came to 15' to a first time tried call.
Monday I tried a totally dif reeds and all call. That was Marks bird. Couple hours later I had another call in mouth, killed that bird.
Yesterday I was working a kids fish derby. My buddy Bob came over said the call I'd given him, yet another style he used it successfully on a bird. Not sure how many times he was out but within a week 4 dif birds w 4 dif calls. Neat in a way