If you have ever participated in a road race, triathlon, or stair climb, the odds are good that you have some familiarity with chip timing. Chip timing is the leading method for timing and scoring road races, using small transponders embedded in the namesake plastic chips to get highly accurate results. As a race timer, it is my job to set up the equipment used for chip timing and to interpret the data properly to provide race participants with accurate results.

I deal with a seemingly unending flow of questions at these races while I set up, tear down, and monitor the equipment and by far the most frequently asked question is, “What was my time?” The second most popular questions are about how chip timing works. The answer to the first question is, “Results will be posted shortly.” The answer to the second question is slightly more complicated.

Chip timing at its most basic can be described as such: chips are read as they go over the mats, giving participants their time. The reality is slightly more complex than that, however. The chips themselves are essentially passive radio transponders embedded in plastic and given unique identification numbers, called chip codes, which are assigned to each participant when we put together the race packets. The chip codes are read when they pass through the fields created by antennas embedded in mats on the road (or on beaches, or at the top of stairs, depending on the event). The mats themselves are powered by boxes, which act as power sources for the antennas so that they can create the fields that read the chips. The boxes pass power on to the mats, which pass back information collected when a chip passes through their field. This information is sent to decoders that are connected to the boxes. These decoders hold the raw data from up to eight mats at a time to be passed on to computers by being either cabled directly to them or by being set up to transmit wirelessly.

The data collected on the decoders is stored in the form of time-of-day reads; whenever a chip passes over the mats, the time of day that particular chip registered is recorded down to the hundredth of a second. My boss explained to me when I started that getting the data is the most important part of scoring a race, as you can always work on interpreting the data later. Computer programs are used to interpret the raw time-of-day data in many different ways to provide race directors and participants with incredibly accurate and detailed results.

The most basic of chip timed races require only a start line and a finish line, providing timers like myself with two sets of time-of-day data; we run programs that essentially subtract the start time from the finish time to get the time it took participants to complete the race. It sounds pretty easy on paper, but consider that each chip is tied onto the shoe of a human being, and with each human being you have dozens of variables and opportunities for human error to muck things up. Chips can only really be read if they are directly above the mats, so we make a point of printing instructions on every participant's packet that they must wear the chip on their shoe, stating in plain letters at the end, “No chip, no time.”

A warning label on every packet is still not enough to deter some people from coming up with truly inventive ways of not wearing a chip. My personal favorite exchange came with a man who was shocked (just shocked!) that he had no results. I asked him if he had a chip, as that was where the results came from, and he replied that he did, so he should have results. I asked him where he wore the chip, as a chip worn in a shirt pocket or somewhere else might not have been read. He casually replied that he left his chip in his car.

Because of the inevitability of human error (multiplied by however many hundreds or thousands of participants in a given event), it is important for race timers to employ backup systems to catch errors that would be lost in a sea of raw data. There are two main backup systems that I use at almost every race: a second line of mats referred to as the “backup line” and a device called the Time Machine that is operated manually by either myself, a coworker, or a trained volunteer. The backup line is set up the same as the other mats (which are referred to as the “primary line,” or “primary”, in these instances) and can be used to see if anyone was missed going over the main mat and sort out discrepancies in the order in which times appeared on the primary line. Almost every finish line you see at a race will have a backup line behind it. Splits, which are mats set up at larger races to collect data at certain points like the One Mile marker, almost never have backup lines.

While the backup lines can help sort things out for people whose chips are worn properly, the Time Machine is my safety net when it comes to dealing with human error. The Time Machine looks a lot like an old-school adding machine--the kind you see accountants using in movies--and it works pretty much the same way. The machine itself is synced to the chip timing equipment so that they display the same time of day down to the hundredth of a second. The person operating the Time Machine then types in the bib number of a participant as they approach the finish line and hits the 'enter' button as their foot crosses the line. The time of day that person crossed is then printed next to the bib number on a roll of paper. Although this method of timing--called “select timing”--cannot account for every runner in large races, it provides a good record to check against the raw data to make sure the order and times are correct for participants. Time Machines are also a great way to record the times of people you suspect didn't wear a chip on their shoe, allowing timers to manually put their time into the results despite their inability to follow directions.

Using a Time Machine to assign finish times to people who forgot or lost their chips leads to another question many people have: what would the start time be for someone who doesn't have a chip on or who doesn't cross the start mats? The answer is fairly simple: they are assigned the universal gun time. Race scoring has two main settings: gun time and chip time. Chip time is the difference between the time a person's chip registered on the finish mats and the time it was read on the start mat while gun time is the difference between the time the person's chip registered on the finish mat and the time that the race officially started. Gun time gets its name from the common practice of using starter pistols to signal the official start of a race. Although most races use chip time as the official result, there are some that score races off of gun time. Some races use a combination, with the elite waves of runners being scored off of gun time, while the general population is scored off of chip time.

Once a race is finished, it is the job of the timer to make sure all the data is accurate and then to run various programs (often written specifically for the event per the race director's request), to interpret the data. Although most events have prizes or recognition for the overall winners, male and female, it is also very common to recognize age group winners. Age group winners are the people with the fastest time out of everyone of their gender in a certain age range. Age groups are primarily broken down into five or ten-year spans, for example, males age 30-35 or females age 30-40. Age groups are a great way to award more participants for their times as well as increase the number of people looking to join an event. Some of these computer programs to interpret data are used during the race to give preliminary results for the people who have already finished and have to leave before the race is completed, while other programs can be used to make sure that everyone who started a swim in a triathlon is out of the water safely or that nobody has gotten lost or cut the course in a marathon.

Although the basics of chip timing have remained fairly constant, there have been a great number of advances in the field in recent years. Newer systems have come out that have the identification numbers on the back of the participants' race number bibs instead of on separate chips. These systems are fundamentally the same as the chip systems in their set-up, using a line of mats connected to a decoder to gather the raw data. The equipment for bib timing, as it is called, is manufactured by the same companies that make the chip systems and uses the same software to interpret the data. These new systems come with a number of advantages: they require less equipment to operate, have much smaller mats than the chip systems, and offer participants a simpler way to be timed – all they have to do is pin the bib to their clothing.

Bib timing systems are not without their own set of challenges, though. Because they use a larger field to read the ID tags on bibs, there is the added logistical issue of keeping finishers and spectators who are wearing bibs of their own far enough away from the mats that they will not be picked up and have to be removed from the results. These systems are also impractical to use for triathlons, as the water and transitions would hinder the usefulness of the bib. Although chip timing is still the leader in this field, bib systems offer a great new way to time road races that is quickly growing in popularity.

The other big change in race timing in recent years is the ability to disseminate data and results to people in faster and more user-friendly ways. Driven by the prevalence of smartphones and social media, there is an increased demand for faster result turnover. It is not uncommon for people to be on their phones checking to see if their results are online before they even leave the finish area of a race, and I often have one or two emails from participants before I am even done loading my equipment into the van to head home. Larger races like the Twin Cities Marathon address the demand for data by offering text message updates to friends and families as soon as a racer crosses a split and have results posted online in real-time streaming. It is also very common for races to now feature an email blast, where participants are emailed their results and a link to the overall race results immediately after they are posted on our website.

Chip timing will continue to move forward as new systems get easier to use and current systems get more portable. Results will become more and more detailed and entertaining for participants to look at. As things move forward, my job will become more and more complicated. Should you see someone at the finish of a race who looks moderately official and is working with the timing equipment, thank them. And please, please, please do not ask them what your time was unless you have actual concerns. Do feel free, however, to ask them about how the timing works. We love talking about that.