EP 746 - Double Strand vs Single Strand Uni Knot Data

Tom Rowland, host of the Tom Rowland Podcast, professional fishing captain based in the Florida Keys, and creator of the How 2 Tuesday series, tests the blood knot for connecting two lines together in this tactical knot-testing episode. Tying 15 pound fluorocarbon to 20 pound fluorocarbon, Tom reveals the exact breaking strength after three tests and whether this classic knot delivers the reliability anglers need for trout, tarpon, and bonefish leaders. If you've ever wondered whether the blood knot is worth the effort or if there's a better option for building tapered leaders, this data-driven breakdown gives you the answer.

Why the Blood Knot Matters for Leader Building

The blood knot has been a staple connection for building tapered leaders across multiple species and fishing styles. Tom explains that this knot is specifically designed for tying two lines together, making it ideal for trout leaders, tarpon leaders, and bonefish leaders. The technique works for carbon to fluorocarbon connections and monofilament to monofilament, giving anglers versatility in leader construction. But the real question isn't whether the blood knot can be tied—it's whether it delivers the breaking strength needed when a big fish tests your connection. Tom's systematic approach removes the guesswork by testing the same fluorocarbon combination three times to establish a reliable average. The complete tying demonstration and testing process starts at 00:01:47.

The Blood Knot Tying Sequence Revealed

Tom breaks down the blood knot into a simple sequence that anglers can replicate on the water. The process begins by crossing the lines to form an X, then wrapping four times up before bringing the tag end through the hole. The sequence continues with four wraps back, passing the other tag end through in the opposite direction. Tom emphasizes the critical step of moistening the knot before pulling tight, a detail that prevents heat friction from weakening the connection. After trimming, the knot is ready for testing. The simplicity of the four-wrap pattern makes this knot accessible even in challenging conditions, but execution matters when you're dealing with different pound tests. Watch Tom tie the complete blood knot sequence at 00:02:13.

The Breaking Point: Three Tests, One Average

Testing reveals what theory can't predict. Tom ran three separate breaking tests on the same blood knot configuration using 15 pound fluorocarbon tied to 20 pound fluorocarbon. The first test broke at 9.14 pounds, the second at 11.27 pounds, and the third at 9.46 pounds. The average of 9.95 pounds represents 66.3% knot breaking strength, a specific data point that tells anglers exactly what to expect when the line goes tight. The variation between tests—from 9.14 to 11.27—also reveals how execution and line condition can impact performance. This isn't about whether the blood knot works; it's about understanding the margins you're working with when you choose this connection. The full testing sequence and results breakdown begins at 00:02:44.

What 66.3% Knot Strength Really Means

A knot that retains 66.3% of its rated breaking strength isn't necessarily a failure—it's a data point that helps you make informed rigging decisions. When Tom tied 15 pound fluorocarbon to 20 pound fluorocarbon and achieved an average breaking strength of 9.95 pounds, the result shows how the blood knot performs in this specific configuration. For leader building, where you're stepping down pound tests to create taper, understanding this percentage helps you calculate actual breaking points throughout your leader system. The blood knot's primary advantage is its low profile and ability to pass through guides, but if maximum strength is the priority, this data helps you compare against alternatives. Tom discusses the implications of these results at 00:02:59.

Final Thoughts from Tom

The blood knot is one of those connections that anglers either swear by or avoid completely, and the data helps explain why both camps exist. At 66.3% knot strength, this isn't the strongest connection you can make, but it's not trying to be. The blood knot's value is in its low profile and ability to create smooth transitions in tapered leaders that need to pass through guides.

What I appreciate about systematic testing is it removes the guesswork. When you know your 15 to 20 pound connection is going to break around 10 pounds, you can make informed decisions about the rest of your leader system. The four-wrap sequence is simple enough to tie on the water, and the consistency across the three tests (even with some variation) shows the knot is repeatable when tied correctly.

If you're building leaders for trout, tarpon, or bonefish, understanding exactly what this knot delivers helps you decide whether it's the right tool for your application. Watch the full tying sequence and testing breakdown—it's worth seeing the technique and data together.