Trout to be specific. Small, fresh water and filleted. I know that will be frowned on by the fly rod crowd, but I eat them! I'm blessed to have any at all this year after what Helene did to my state's hatcheries. I've amassed a bit of a collection of fillet knives. Some bought, some gifted. For the last two years I've been on a journey to thin the herd down to a couple that performed best, but I'm stuck at three. I probably should describe what I use them for, but it's pretty much "textbook filleting 101". 1) Slit the belly from gills to vent and pull out the entrails. 2) Slit behind the gills, turn and go down the spine leaving a small tab at the tail. 3) Flip it over and remove the ribcage. 4) Run the blade between the flesh and skin from the tail to the gill end and basically skin the fish, removing any scales with it. My collection consists of a 4" Rapala, a 6" Rapala, a 7" Berkley and a 6" Normark. They've are all touched up before and during cleaning with one of those "pull through' coarse/fine ceramic rod "V" sharpeners. just because I don't have a good alternative for flexible blade knives with my guided systems. For step 1 the winner is the 4" Rapala, just because its short length and I wish it were 3". For the step 2) spine cut, the surprise winner is the 7' Berkley , because I disliked it on sight and don't need the extra length. For the step 3) rib removal the 6" Rapala excels, most likely because of length again. For the step 4) skinning the Berkley was the clear winner again and I don't understand why. I thought the Normark would earn a spot on this starting line up. The Berkley is overly long, I don't care for the ergonomic finger grip, made in China and yet it's emerged as the star! All these knives were measured with a digital Vernier caliper and all blade thicknesses were .05-.06" tapering thinner toward the tip. I'm aware some of them I think are made by the same company. The Normark was the only one that appears to have a primary and secondary factory grind. With the pill-through type sharpeners I can usually l tell when the blade has bee "touched up" by the "resistance" on the pull smoothing out as well as any chips and "problem areas". The anomaly is the Berkley. It always feels "rough as a cob" drawing it through the sharpener, so much so that I thought I must be removing metal on "shoulders" and not at the apex. But by finger touch or shaving hair methods, it always touches up scary sharp and out-performs...go figure!