The issue is you are calling it ping, when it's hardly consequential - sure it can affect the game, but I'd defer to Exselsior's explanation.
The 'lag' problem in most cases can be traced to two primary sources:
- bandwidth - can a player sustain the needed throughput to receive and send packages to every other player. Even if the player has the best PC out there, if the player can't send and receive data at required speed, it will lag.
- simulation - even if the player has the best connection out there, if a player's PC can not calculate what to send in those packages fast enough, it will lag.
Regardless, the idea with the visual seems really interesting actually, but I see 2 problems with it, assuming you measure the above-mentioned things, and not ping that is borderline irrelevant unless you are playing from the low-Earth orbit on the other side of the planet (though feel free to argument otherwise):
1. Players could be running something in the BG while waiting for the lobby to fill.
As the 'title' states. This could affect both bandwidth and simulation testing. The solution to this could be you plea players to turn their stuff off before starting the game (a.k.a. putting the PC in the state it will be in while the game will be running), but I don't see how you could enforce this - hence, there will be some who will disregard this recommendation, and after a while, everyone will.
2. Who's the lagger?
Let's assume you have 3 players that are in a lobby - A, B and C . Let's run a little thought experiment, assuming all players have relatively low ping (<300, which in truth only means they are 'very close to each other', network-distances speaking).
A has awesome internet, both up and down way beyond necessary, and has perfect connection to both players B and C. Let's assume player B has a decent enough connection, where it's good enough to support what is required to have a smooth play. Player C, on the other hand, has a bit worse internet connection, and for some reason (not unrealistic), his connection to A is completely stable, while his connection to B is absolute chaos.
Hopefully I don't have to explain how player A could not be able to tell who of the two players was the source of lag - even if he had insight on their own points of view. And if he were the host, he would not be able to decide on who to kick. The situation gets even messier the more players you have of course.
If we are already thinking of a way to represent "connectivity fitness", why not, if possible, extrapolate that from the last few games (say 20)? Measure both connectivity and simulation rates (not sure if it's possible to do that, or if 1 player bottlenecking causes everyone to have reported reduced sim speed) during the game, and extrapolate a 'score' out of that.
To make sure data is more representative, you add weight(multiplier) to the score, depending on how many connections had issues - e.g. if you're lagging with everyone (from your perspective), you get a higher weight, if you lag with only 1 person out of say a team game of 12, you get less weight on your score (though in-game it'll probably play out the same, that is game will lag for everyone, but that's the exact purpose of the weight, to not punish players because they had a 'lagged' connection to someone because of that someone).
In order to make the system even more fair, you could keep independent scores for each player count. Reasoning for this is, often lag is not due to poor internet connection, but due to player's PC not being able to handle the simulation at proper speed. E.g. even though a player might have 100000 exabytes/femtosecond of upload and download speed, if he is playing on his mom's clothes iron, he won't be able to utilize that because his game is lagging internally. But, this might be due to him trying to play 50 player games, and maybe his rancid potato can handle 3v3 (and less players) amount of games without a hitch - so you don't want his score to look abysmal when he would actually run perfectly well in smaller games.
- this one, I'm talking from experience, I do not lag whatsoever in 4v4 games, but start having sim speeds in 6v6 and larger, which presents itself as lag.
Anyways, once you have a score, you can represent it by a simple circle, and a few colors. Say 3: green for 'great', yellow for 'good' and red for 'bad'. You then have 2-3 such circles, maybe representing (as before mentioned) your overall score in last 3, 10 and 20 games - so you don't get nailed by random noisy data. First one might be red, but if 3rd is green, you know that the player in general has good connection.
Another 'problem' could be that players run into 'bad rating hell' of sorts, where they get a red rating, so green rated players refuse to play with them, so they can only play with other red-rated players, but because of disproportionate lag in those, they get stuck on red rating.
In such a case, you could have an automated 30 second game simulation where a virtual game would be simulated, measuring connectivity to the server, but simulated as several ports, and measuring average game simulation speed at several units amount values, to see how well your PC can handle those.
This functionality would have to be used 'manually', a.k.a. there would be a 'Test connectivity' button somewhere in the settings menu, and it would just start a game u for you, you'd wait, not do anything, and then you'd get a 'fresh score' (then you'd get the first circle be in color, and the other 2 in black, so other players knew you 'reset'). The problem of 'you can login somewhere else and run a simulation on a better PC just to play on a worse one' can be solved by also gathering system hardware data, and invalidating the 'reset test' for the next several games if discrepancy is detected.
