A runner who leads every pack and then vanishes
In an amateur context, I've paced about a half dozen races, half marathon and marathon distance. I've also served as a pacer for runners in the second half of a 100 mile race a couple times.The purpose of a pacer for amateur runners is to set a consistent pace and provide encouragement to runners who may be running their first race at that distance. Or maybe someone trying to set a new PR. Since most courses are not flat, I actually try to run even effort, and explain that is the plan to the runners I'm pacing. So we slow down on the uphills and speed up a bit on the downhills.Yes, runners can use a variety of electronic devices (GPS watches, heart rate monitors, accelerometers on your shoe) to try to set their own pace but none of these are perfect. They also require constant attention. And they don't provide moral support.Even though I'm a fairly experienced runner (25+ marathons), I'll join a pace group myself when running a new course sometimes. A marathon can be mentally exhausting and it's sort of like being able to run on cruise control if you can just fall in next to someone else and rely on them to set pace.Running in a pack is also just easier, not even considering the wind breaking potential depending upon speed and prevailing breeze.On the 100 mile races, runners may have been on their feet for 12+ hours by the midway point and are starting to run into the night. Pacing those runners is really just about moral support and encouragement. Typically they are allowed to pickup a pacer after the 50 mile mark and I'll keep a single runner company for say a 12.5 mile lap and then they can switch to another fresh pacer. So they may get the company of 3-4 pacers in the second half of the race.Another example is that large marathons have guide runners to help those who need assistance. Visually impaired runners. Maybe runners with prosthetics who are concerned about being tripped. Etc. I've never been a guide runner but I'd like to some day.Pacing the 1:50 group in a half marathon:https://i.ibb.co/4gRTjjT/FCC9720-D-4-E4-E-4-F74-91-EF-2-FCB2...