Groups of gliders can be quite fast, or they become lumbering slow masses that get in each others way. They are a staple of high level racing, to the joy or more likely the misery of most competitors. Gaggles are an integral part of racing because of their services in risk mitigation. Flying with 30 gliders nearly guarantees that if there is a thermal, it will be found. Furthermore, when the going is good, gaggles and especially smaller packs can be really fast. Why do they behave this way?
And how can we take advantage of their behavior?
Fundamentally, a gaggle consists of many individuals who are acting in their own interest, but the cumulative actions leading to a group consensus. Think of starlings in a mass. This individual behavior is based upon the weather conditions ahead and what other gliders are doing. This affects how the leading elements of the gaggle set the pace and ultimately the behavior of the whole pack. The “leaders” may be a team or a collection of individuals who are more or less cooperating.
Whenever pilots are flying with company, they ask two questions:
- Am I trying to beat these other pilots right now? Yes Performance optimization approach
- Do I need these gliders as markers to stay in the air? No Risk mitigation approach.
The collection of judgments of individual pilots, especially those who are at the “helm” of the gaggle leads to the group acquiring an optimization or risk-mitigation approach.
Next, given the “frame” in which the gaggle is operating, will determine a general set of behavior. The behavior is driven by loss aversion, it’s just a question of which kind.
For the optimization approach, if the leading elements start speeding up, the loss that few want to accept is getting dropped and losing points on those pilots. If the leading elements grind to a halt, then the folks behind start seriously contemplating the possible loss of dropping out of the sky. This leads to the risk-mitigation approach.
Given this behavior, the group will then take it to more extreme degree.
If the leading elements of the pack are in an optimization mindset, they will generally fly closer to optimal MC speed. In turn, the folks behind them will see the leading elements of the pack flying quite fast and will generally go with them. Their objective is to catch up. What do most people do when trying to catch up? They fly faster! The result being that the gaggle will push quite hard, with many elements of the gaggle overflying the MC speed in the process. Interestingly, one of the byproducts of gaggle flying is that it is possible to fly in much better air due to the presence of all the gliders marking what it happening in cruise. As a result, overflying the MC speed may not be inefficient due to the extra “netto” rising that pilots find and the L/Ds achieved are comparable to flying closer to pure MC. The result is a very fast moving group!
However, if the leading elements of the pack go into a risk mitigation mindset, this leads to what I call the classic gaggle “bottleneck”. This happens when the leading gliders all decide that they want to merge with the gaggle and need other markers to stay in the air. And this creates a situation where the gaggle causes something like a multi-car pileup, with the folks behind slamming into the slow blob.
This leads to a number of “classic” behaviors. One is that no one will want to lead out. The second is that any instance that a glider circles, it will attract the attention of those behind. The third is that the gaggle will fly under-fly MC speed since it is unattractive to lead out. Specifically, it is the terrible fear that someone behind you will find a thermal and you will be forced to go back, below everyone. There is no incentive to lead out and every incentive to watch what everyone else is doing. The end result is the notorious, inefficient gaggle that many people despise.
How to fly the pack?
Gaggle Flying an Optimization Approach:
When the gaggle consists of pilots trying to beat each other, the gaggle will be quite fast. The goal is to stick with it, work the air and center effectively. Pilots will fly aggressively, leaving when optimal and fan out in the cruise to better and center thermals quicker. When a pack is flying like this, it is very unlikely that an individual pilot will make consistently more optimal decisions. The reason is that each pilot is independently considering what are the best clouds, lines, etc. The group consensus of decisions reached independently is generally better than even the smartest individual. This is known as the “wisdom of the crowd”. Each pilot looks at the sky differently and sees information that perhaps others don’t process. When many pilots do this, this means that the collective output is usually the right one. A contrarian view is very likely to be wrong, or at a minimum a high risk proposition with little reward.
As such, the primary goal is to avoid getting dropped off and maintaining an energy advantage on the pack you are flying with. Do not race from below! The pack can drive itself into the dirt and the pilot might find himself too low to dig out. If the pack is higher, take a thermal higher and allow some distance to develop. This is much less risky and it also affords the opportunity to merge in the next thermal with no centering loss.
However much people despise survival gaggles, they afford probably the biggest competitive opportunity available to a racing pilot. And it’s best to learn how to exploit it as gaggle flying is integral to world level competitions. Why is this? The pilots are too good and the pack mitigates more risk than it loses in inefficiency. Even when the gaggle is very slow and is acting in desperation, generally the expected value of doing something different is dramatically lower than flying with it. So in essence, if you can’t beat it, you must join it.
However, this does not take away from the fact that it flies inefficiently. So if a pilot finds ways to exploit this inefficiency, there are massive gains to be had. This is in contrast to the optimizing gaggles, where the gains will tend to be pennies compared to the opportunities afforded by slow gaggles. Secondly, if done correctly, exploiting the gaggle affords the pilot the ability to have these gains with a proportionately smaller risk.
Strategically, the goal is to predict and exploit gaggle bottlenecks. Bottlenecks occur at any time that there is a sharp increase in risk aversion, or in essence a big downshift. As the risk aversion increases, the more drastically inefficient the gaggle becomes. Examples of this condition are
- Day drying out from cumulus to blue
- High cloud cover moving in.
- Heading into a less soarable area: wet ground
- Approaching a challenging turnpoint, especially upwind.
- Weak final glide* (Will explain in more detail)
The best places to be are to either clear the bottlenecks before the gaggle stumbles into them, or be behind the gaggle and work your way to the top as the gaggle slowly lumbers along.
Clearing bottlenecks before the gaggle gets there generally require starting earlier. This can be quite risky, but massively rewarding as well. This works if it is possible to clear the challenging points. However, by virtue of the fact that these points are challenging, there is a substantial risk to the contrarian pilot. One must be very confident about the timing of the bottleneck and clear it without himself dropping out of the sky.
The other alternative is starting later than the pack and catching up when it slows down. If timed correctly, this can also be quite rewarding as the pilot is able to cash in all the time he had started behind. However, one must be quite careful to not be dropped off the low part of the gaggle.
In the later starting condition, the pilot must assess how much time he is trying to gain. Start too late and the pilot will stumble into the weak conditions without help from the pack. Too early and he will be the sheep eaten by the wolves behind.
Exploiting the Gaggle:
Once the pack is in sight and it has slowed down, now it is the time to push just a bit more. The goal is to integrate oneself in the middle and eventually the top of the pack. This can only be done if the pilot flies more efficiently than the pack. This is done by:
- Flying closer to MC speed
When the gaggle slows down to best glide and everyone is watching everyone else, this is a great opportunity to push a bit faster and gain on the glides. Going MC 1.5 knots when the lift is 1.5 has a massive gain in achieved speed with very little loss relative to those who are flying MC 0.
- Taking stronger climbs
It is very tempting to just merge in with the gaggle as soon as possible and from a lower altitude. This is senseless and quite risky. Instead, cover the gaggle from behind and work an energy advantage on them. Being outside of the gaggle lets gliders generally climb a bit better, but there is nothing wrong with climbing at the same rate either. Gaggles tend to leave thermals a bit too early or too late. When they leave early, stay with the climb longer and let them search around inefficiently for the next one. If the folks you are flying with are staying too late and there are marked climbs ahead, leave. Flying with a pack is the best time to fly MC speed.
- Working better air in the runs
With many gliders in the cruise, there are many gliders to work with. As they bop up and down, weave in the better air. This is best done by “offsetting” your glider relative to theirs. Do not follow directly behind someone as this makes it more difficult to consider the relative gains. Try to stay behind and in the middle of the pack that is running as this gives the greatest optionality to work the air.
- Avoiding “stupid” turns
Slow gaggles will do many searching turns and gliders will join them, hoping for a climb. Whenever you see someone turn, watch them carefully to see if they are climbing. If they are not, move on! These searching turns are very costly.
Lastly, once at the top of the gaggle, now it is time to downshift and work with the pack. Congratulations, you’ve gained a considerable amount of speed. Now it is time to make the rest of the course holding onto that gain and avoiding trouble. A classic mistake is to take the “inertia” of having worked up the pack and being overly aggressive in trying to drop it to then get run over by the pack later. Don’t let that happen to you.
- Once on top, knowing how to “pop” the gaggle
Getting groups of risk averse gliders to leave can be quite difficult and there is a bit of an art to motivate them to leave. Depending on how bad the day is determines how long you need to let the gaggle “cook” to get folks to leave. When no one wants to leave, there are two forces at play. The first is that no one wants to be ahead of the pack as it is extremely costly to make a radical deviation that is found behind you. The second is the impatience at sitting in very weak to non-existent lift, losing time and possibly altitude. The goal is to time the frustration and impatience well enough that leaving will cause the impulsive reaction of others to leave with you.
My preferred method is to let the gaggle cook until the lift nearly completely drops off and leave along the wind-line at minimum sink. This works if the wind-line is within 90 degrees of course line. The act of leaving when folks are dying to go is generally enough to prick the bubble. Leaving along the wind-line keeps me at the same altitude or possibly even allows a gain on the rest of the pack.
Often times on long tasks, the final glide point will cause a bottleneck of sorts. Generally the conditions start to weaken and pilots will become a bit overly risk averse. This is driven by the “certainty effect”. People are generally very uncomfortable with a 99 percent assurance of success when they could guarantee nearly 100 percent. Psychologists and economists have shown that people will pay a considerable amount to ensure certainty, even when the gains are objectively small. In soaring, after going such a large distance, there is a strong loss aversion to coming up short. Coupled with the fact that most pilots are getting quite tired after a long day in the cockpit, they are willing to overclimb too much in too weak lift.
This bunches gliders up on the last leg and affords a great opportunity for a pilot who is somewhat more risk seeking. For one, there is the opportunity to bump through many of the marked thermals. It helps to get “in the game” mindset shortly before the last turnpoint and be mentally fresh to perform strongly on the last leg. Doing so can result in a large gain on most of the competition.
Generally speaking, pushing just a little bit when everyone else backs off are the greatest competitive opportunities in high level racing. When things are going well and everyone is flying fast, it is very difficult to do anything that will cause a large difference in score. However, when everyone is flying slow, this will cause the risk averse gaggle dynamic that creates exploitable inefficiencies. Timing them and exploiting them effectively is how one wins a world championship.