Race start types

RaceSplitter supports the timing of four different race start types

Mass Start

In a mass-start race, all the participants start at the same time. This is typical of races such as a 10k or mountain trail running race. In this type of race, you start the timer when the race starts, and then time the participants as they finish. (You can, of course, also time intermediate points on the race as well.) If the race is not lap-based, you’re likely to want to disable the auto-lap feature.

Interval Start

In an interval start race, participants start one at a time, and separated by a fixed time interval, such as 30 seconds. This is typical of races such as nordic skiing and cycling time trials. In this type of race, you start the timer when the first participant starts , and then time the participants as they finish. You don’t time the participants as each one starts; rather, RaceSplitter knows, based on the start list and specified start interval, when each participant starts and then automatically adjusts their finish time to account for their start delay. For this reason, in interval start races, it’s critical that each participant starts on time, and in order!

Wave Start

Wave start races are identical to interval start races, with the exception that more than one participant—i.e. a “wave”—can start at any interval.

Variable Start

To support situations in which individuals or waves of racers start at non-fixed time intervals (or manually), RaceSplitter provides a variable-start support mode. This mode, which is a special configuration of a mass-start race, isn’t natively supported in the app, but depends on the RaceSplitter.com website.  For me details, read the article: How to time a variable start race.

Super-Important Warnings about Wave & Interval Starts

In wave and interval start races, the start order of all participants is specified in the start list you create on the race in RaceSplitter. And since you’re also specifying the interval and wave separation times, this means that you are also specifying the start time of every participant.

So in interval and wave start races, once you start the timer in RaceSplitter, the app presumes that ever participant starts the race at their programmed start time, and if that doesn’t happen, the results can be catastrophic. Why? Because when each participant crosses the finish line, RaceSplitter will computer their effective race time by subtracting their start delay from the recorded finish time.

Here’s an extreme example of what can go wrong:

Imagine you have a wave-start race, in which participants typically take an hour to finish, and you have 10 waves of racers, each starting 30 minutes apart. Now imagine you have a racer who is supposed to start in Wave 3  but who actually started with the Wave 1 group.

So you start the race, and this racer ends up crossing the finish line 55 minutes later. When RaceSplitter records the time of that racer, it will see that he/she should have started in Wave 3, and will therefore subtract 60 minutes (two wave start intervals of 30 minutes) from their time, resulting in an effective race time of negative 5 minutes!

Since a negative race time can’t happen in reality, RaceSplitter will assume the race clock was started late, and will adjust the race time by five minutes, such that that racer will have an effective race time of zero minutes. And that adjustment of the start time will also affect the final time every other racer in the event!

(Similar problems can happen if you have an interval start race, that ends up with a gap (say racer 5 doesn’t show up), and instead of waiting two start periods for racer 6 to start, you just bump everybody up a slot.)

If interval and wave start races carry such a risk, why even have them in RaceSplitter? Well, many nordic events (like nordic ski) have been working like clock-work for generations, and they appreciate being able to time their races with a single device. Also, since variable-start races require access to the RaceSplitter website for results processing, that’s not an option for them while timing in the field.

But for many events, it’s much better to choose “variable-start”, and have two timers — one timing the start, and the second timing the finish. This completely eliminates the above risks. It does require that, in the case of wave starts, you manually enter all racers on the timing-bar, but you’ll learn how to do that quickly through practice.

Beyond the basics

After you've read the Getting Started Tutorial, dive deeper into more advanced topics.

Planning your event

As you plan the timing of your first event, here's what you'll want to think about.

Start types

RaceSplitter supports four race start types — mass, interval, wave and variable.


While the RaceSplitter app supports a single user-defined field, complex categorization is supported at the RaceSplitter website.



This article explains how to publish, export and edit your results, both in the app and online.

Multiple Devices

Easily time intermediate points on the course, with RaceSplitter's multi-device support.

Auto-split Mode

Auto-split mode is useful for timing multi-lap races, but should be disabled for most others.

Bibless timing

This article explains how to create timing entries in rapid-fire mode without entering bib numbers.

The Timing Bar

The RaceSplitter "timing bar" allows you to assign the same time to multiple racers — useful when timing groups of people arriving together.

Racer Compensation

RaceSplitter supports the application of compensation factors in adaptive and handicap sports.

Automatic start time adjustment

Under certain circumstances, RaceSplitter will automatically adjust the race start time. This is both a benefit, and a risk.

We’re here to help!

If you’ve been unable to find what you’re looking for, don’t hesitate to contact us, and we’ll get back to you shortly.