[MercilessMing]

Well I invented an example and played it a few rounds, and some things popped out at me.
Piloting tests stop you from losing, but being a getaway driver means lots of Edge.
It actually seems difficult to win by escape.  Pursuers merely have to meet their handling threshold and they stay in.  They can even gain on the target automatically, negating the effects of maneuver edge actions from the chase target meant to get the chase target closer to the Escape! Edge action.
When all the participants are competent enough to always meet their threshold, chases will really only end through combat.
To make escape easier, a strong driver should try to change the environment to Tight, and use increasingly difficult handling tests to force crashes with the Up the Ante.  In Open or Restricted environments, if drivers can meet their handling threshold, it's too difficult to maneuver pursuers to extreme and hit Escape!.
I think most chases will just be backdrops for combat rather than wars of maneuvers.
In the case of foot chases, chase targets have almost no options to maneuver!  All three edge actions that prevent pursuers from gaining are Piloting only.  Oops?
So pursuers who pass their athletics test will catch you and there's not much you can do about it.

[Typhus]

I'd definitely want to see a few chases play out on a stream or something to get how they work.  I get the concepts, but it's hard to gauge how the Edge aspect works out without seeing it played a few times first.

[MercilessMing]

It may not be obvious, the way it's written in the book, so I'll write out how chases work in more concise language:
When starting a chase sequence, the GM determines the environment - Open, restricted, or tight.  This modifies the threshold of the skill check every participant must make each round to stay in the chase.
Relative starting positions are also set.  They're expressed in distance buckets, relative to the designated chase target and align exactly to weapon ranges: Close, Near, Medium, Far, Extreme.  In vehicle chases, Close maps to 0-10 meters.
Speed is also set, but speed plays no part in chases until you crash.
Every combat round, on their turn, each participant must spend a major action on a skill check to stay in the chase - Piloting for vehicle chases, and Athletics (sprinting) for foot chases.  If they don't spend the action, they're out.  If that's the chase target, the opponents have caught them and the chase ends.
The Piloting/Sprinting roll is not opposed, it's against a threshold set by vehicle handling and modified by the environment.
All the chase mechanics are tied up in this roll.  All the edge is gained and spent here.  So it's worth breaking it down:
1 - Grab some dice.  Do not modify your dice pool due to speed interval.
2 - Distribute Edge.  This section of the rules may be broken but here is what RAW say:
     a. Compare the highest "Relevant Attribute" on each side.  Award one edge to one member of the side with the highest Relevant Attribute.  Since this isn't an opposed roll, I think the intent is to award this edge only once per round.  (The Relevant Attribute is either Speed Interval or Accel, and is determined by the current Environment)
     b. Award 1 edge to one member of the opposing team that has Positional Advantage over you.  If no opposing members have positional advantage over you, and you have positional advantage over any opposing members, gain 1 edge.
     c. VCR users gain 1 edge.
Any edge you gain can be added instead to the Chase Pool, where it does not count against your 2/round max.
3 - Roll Dice and Spend Edge.  Chase Edge Actions are special in that although they must be declared before the roll, as normal, they only take effect and you only spend the edge IF your Piloting/Sprinting roll is successful.
Take note of whether you passed or failed your skill test.  If you failed, you're piloting a vehicle, and the Environment is Tight, determine your speed now and make a Crash test.  If you failed, you're sprinting, and the Environment is Tight, resist 4S damage with Body.

At the end of the round, everyone who succeeded on their Piloting/Sprinting roll and is NOT the chase target may move one range category closer or farther from the chase target.  Everyone who succeeded on their Piloting/Sprinting roll this round is considered to have Positional Advantage over everyone who did not succeed next round.

[Typhus]

Yeah, all that tracks with what I understood as well.  The Step One and Two sections do a decent job of conveying it.  It gets confusing on the second pass where it explains the same rules over again, but not as clearly. 

I more mean that seeing it play out would help give me an idea of how one would want to run it, play with their Edge actions, wrangle multiple vehicles, etc.  Showing off the flow, using Qualities for extra buffing, that sort of thing. 

 

[MercilessMing]

Oh, I was writing that out as much for my own benefit as anyone else's.  I didn't realize that the Edge awards were written in a way that doesn't quite make sense until I wrote out step by step what to do.

Maybe SSDR could get some clarification here, but in the book, there are many instances where it's implied that piloting rolls in Chases are opposed, which they're not. 

Gaining Edge in
a Piloting Test
First, instead of comparing Attack Rating to Defense Rating: compare either your Speed Interval or Accel to the highest equivalent rating among your opponents. Whichever side has the greater rating gains an Edge. In the case of multiple opponents, the gamemaster determines which character (PC or NPC) receives the Edge. Only one Edge is awarded.  Second, for the situation: Check to see if you have a position advantage against your opponents. If any opponents have positional advantage, one
of them gains an Edge. If you have position advantage over any opponent, and no opponent has a position advantage against you, gain an Edge.  Third, for the gear: All riggers gain an Edge whenever they make a Piloting test. Some qualities or gear might award Edge in specific circumstances.

I bolded the sections that I think imply an opposed test.  I can't think of another example in SR6 where a Simple Test invokes awarding edge to characters that are not currently acting.  I'd really like clarification on the intent for edge awards during chases.

The section on Positional Advantage also implies that the piloting tests in chases are opposed:

Position advantage grants a situational Edge on an Opposed test against a target. This includes Piloting tests, but also any gunners or passengers who target the vehicle with attacks, spells, or any other action that calls for an Opposed test.

There's only one time I can see that a piloting test will be opposed during a chase and that's ramming.

Speed Interval represents a vehicle’s ability to handle high speeds and is used instead of Attack and Defense Rating in a chase—except within a tight environment.

What invokes AR and DR in a chase other than attacks? Is this just a very badly worded restatement of Speed Interval's use in the piloting test?  Or are you really supposed to ignore weapon stats and compare Speed Interval when firing machine guns from your car?

Reading this section carefully, I am left with the impression that piloting tests were opposed in an earlier draft, and I'm seeing the vestigial remnants of that. 

Back to edge awards - granting edge to the opposition when you're not doing an opposed roll screws things up.  Let's say we have a chase where the chase target failed their piloting test and the sole pursuer succeeded.  On the next turn, the pursuer has positional advantage. 

Check to see if you have a position advantage against your opponents. If any opponents have positional advantage, one of them gains an Edge. If you have position advantage over any opponent, and no opponent has a position advantage against you, gain an Edge.

On the chase target's turn, the pursuer gets an edge because an opponent has positional advantage.  And on the pursuer's turn, the pursuer gets another edge because the acting player has position advantage and no opponent has position advantage.  I don't think this is intended.  Imagine this scenario: a suzuki mirage (interval 30) is chasing five Nightsky's (interval 10).  The mirage automatically gains positional advantage due to its much greater interval.  On its turn, it gains an edge due to its positional advantage.  But it also gains another edge on each of the Nightsky's turns, for a total of 6, if its chase pool was large enough to accomodate.  We can agree that the chase will probably not end well for the Mirage regardless, but recognize that the more Nightsky's it was chasing, the more its Edge was fueled, and that is nonsensical. 
I thought awarding Edge only once in the round for the team with the highest Interval/Accel was RAI, and that may or may not be, but surely awarding Edge on your turn when you have positional advantage is RAI.  And since that's RAI, I don't see why awarding opponents edge for positional advantage on every action wouldn't also be RAI.
Either way, I'm confused, it seems broken, and could use some discussion or insight.