Breadboards and jumper wires are so inexpensive today that they get tossed into orders as freebies. The modern jumper wires are so nice to handle with rugged ends. There's a downside to these products. The cheap breadboards don't grip as well (increasing resistance), lack a ground plane, may have other dodgy electrical properties, and simply seem cheap in appearance compared to a old 3M breadboard. Likewise, while the modern jumper wires are convenient they often result in a rat nest of wires. However, a breadboard laid out well with the older 3M jumper wires, is closer to a work of art.

Another problem with the modern jumpers is they can cause intermittent open circuits and have a wide variation in resistance for the same length jumpers. Having lost time due to an open jumper, I checked the other jumpers of this style in my kit. This was the only one that was open, but others, with each length, varied up to 6x the resistance of the lowest resistance jumper of the same length. Both are unlikely problems with a simple length of wire. Be aware of these potential problems, because losing time with inferior products is not worth the product savings.

Good ol' 3M jumpers vs. dodgy modern jumpers

Open circuit modern jumper