That's one or two chip reads out of 100 being blocked by covering the chip with a body part.

By doing so, the arm blocks the chip read about 1 or 2 percent of the time. They cross their arms over the BIB to shut off their smart watches. I've seen missed chip reads mostly from athletes crossing the finish line, crossing their arms over their BIB numbers (and thus the chips as timing chips for runners are usually attached to the back of BIB numbers). It's nice to have a backup just in the very very rare instance that your chip is not read. Sometimes chips are missed by the transponder decoders, sometimes the chips themselves in bibs or on ankles go bad and do not transmit, sometimes you can accidentally block these chips with body parts or with clothing if you wear heavy clothing over your BIB or Ankle Chip. Even the best systems do not guarantee 100 percent chip read accuracy. Where these personal systems come in handy is for training, and for competition when the timing system fails, usually for a missed chip read. My particular system is used by the Olympic Committee for Olympic timing, so I would not question the accuracy. They link to satellites for GPS precision time accuracy and there is never a question of accuracy IF the chip is read. Professional chip timing systems cost tens of thousands of dollars (and I know this first hand) and they are accurate to one thousandth of a second. The question they should be asking is why are their smart watches and apps off by a second or two. They tend to take their watches and iPhone running apps as Gospel, and they want to know why the chip timing system is off by a second or two VS their personal timing device. However, I do have issues with athletes that want to argue with me about their finish times. I think smart technology for endurance sports (Running, Cycling, Swimming) is one of the greatest things to happen for endurance athletes. I'm a multisport Race Director and an Ironman Triathlete.

Strava vs runtastic