Spinnerbaits come in every size and color combination imaginable, and while they are predominantly seen as bass lures, they can be equally effective on northern pike and muskies. In addition, very small spinnerbaits will catch panfish.
Walk the aisles of most tackle shops to examine their bass spinnerbait selection and one thing you might notice (if you look carefully) is all or almost all the lures on display feature an open-loop line tie. An open loop allows the spinnerbait to tumble in the air during a cast without your fishing line becoming looped under the wire. The design makes sense and works well. So why would anyone prefer to cast a closed-loop spinnerbait?
As stated earlier, species other than bass will strike spinnerbaits, and the one in particular that really devours them is northern pike. Unlike bass, northern pike are toothy critters that can cut your line like the sharpest scissors. For this reason, avid northern pike anglers typically add a wire leader to any lure to prevent bite-offs. Using a leader is literally a snap when attaching it to a closed-loop spinnerbait. However, snapping a leader to an open-loop spinnerbait doesn’t work well because the snap can slide along the wire and up to the blades during a cast, ruining the retrieve. Not good.
It’s true that massive spinnerbaits designed specifically for pike and muskies feature a closed-loop design because of the leader requirement. However, spinnerbaits built for bass work well on these toothy predators, so it makes sense to own closed-loop spinnerbaits in a wide variety of sizes and color combinations.
Even in those areas where pike aren’t common, using a snap only (not a leader) on a closed-loop spinnerbait makes sense for bass. If you want to experiment with different spinnerbait sizes, colors or blade combos, then you can quickly change lures with a snap vs. having to re-tie each time.
If your local bait shop doesn't sell a decent selection of closed-loop spinnerbaits, then check out Reed-Runner models from Northland Fishing Tackle. I've used this spinnerbait design for decades with tremendous success on bass and pike.