I struggle with similar ERNs for different types of rods (blanks). In the CCS data for example, there is a 7' Rainshow IP840 which Batson lists as an ultralight, 1/32-3/16 oz lure that has an ERN of 8.03. In the fly rod section there is an Allstar 9' BAF908-4 8wt with an ERN of 8.15. And in the spin section there is another Rainshadow 9' XST-1084F that was built into a rod and it's ERN is a whopping 12.8. I Salmon fish with 8 and 9 wt flly rods, the 8 weight is fine if there isn't a real heavy current. The XST-11084 is a no brainer. The IP840 UL seems to me to be suitable for crappie and blue gills but the 8.03 ERN makes me think it could be used for Salmon - which makes no sense to me. The Allstar with an ERN of 8.15 should fish Salmon fine.

But with nearly identical ERNs, is the little IP840 going to accomplish the task the Allstar will - it's 2' shorter so I would think that helps it out. Thanks.

ERN is power. All those rods have similar power. But, they won't all fish the same because they are different lengths, actions, weights, etc.

One thing you do want to be careful of - the CCS figures given in the database were put there by rod builders at large. There is no guarantee that they are entirely accurate, although most seem to be reasonably so. If you see something that looks a bit off, it might be.

Until the manufacturers begin taking the measurements, you are relying on the work of other builders.

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Most of the power is in the butt section of these rods. So you might see a shorter and lighter rod that you might assume to be less powerful than the longer rods, but in effect it really does offer as much power as the longer ones. The Common Cents Measurements can't lie any more than a tape measure or weight scale can. So if the reading was accurate it is what it is.

I built a fly rod with a IP840 blank. I measured the ERN at about 8.5. It casts an eight weight line just fine. Haven't caught a fish on it yet, though.

Greg