Ok i did some reserch and i come to this data, i dont believe it is correct but it shows figurativly difference leaver makes in start of a game. I made game 1 player and watched his gold gained without doing anything. Then i split amount of gold he got in 4 or 5 people that would play in team and this are results... I believe i am wrong in many things considering this calculation but still i did some work so dont be too harsh on comments.
TIME 5:03
1 PLAYER
GOLD 6247
STARTING 3000
BONUS 5 MIN 2039
ACUMULATED 1208
4 PLAYERS
BONUS 5 MIN 509
ACUMULATED 302
5 PLAYERS
BONUS 5 MIN 407
ACUMULATED 241
TIME 10:02
1 PLAYER
GOLD 9724
STARTING 3000
BONUS 10 MIN 2281 (dont include previous bonus)
ACUMULATED 1196 (5-10 minute)
4 PLAYERS
BONUS 10 MIN 570
ACUMULATED 299
5 PLAYERS
BONUS 10 MIN 456
ACUMULATED 239
TIME 15:01
1 PLAYER
GOLD 13389
STARTING 3000
BONUS 15 MIN 2469 (dont include previous bonus)
ACUMULATED 1196 (10-15 minute)
4 PLAYERS
BONUS 15 MIN 617
ACUMULATED 299
5 PLAYERS
BONUS 10 MIN 493
ACUMULATED 239
From this i get after 5 minutes if leaver wos at start, 4 team players get +163 gold + leavers starting gold (I am not sure but should be 3000/4 = 750). 750 + 163 = 913 gold advantage in first 5 minutes. In this i would like to mention better farming because of better starting weapons considering gold, and pushing opponents to def and lose gold from their tower. 913 gold dont seem much but inical normal creep value is 15 gold => 913 / 15 = 60 creeps difference. And there is thing of better weapon and much better farming and pushing the lane. And i didnt mention here 2 players spliting middle gold and exp and 3 players splitting same gold and exp i am sure it plays nice part too.
Period between 5-10 dont make so much difference, + new 174 gold to 4 players team at 10-th minute. And period 10-15 + 184 gold for 4 players team. From this i concluded that leaver makes difference and disadvatage to 5 players team if he is early leaver in 0-5 min. and that is why i suggested games abour if there is leaver in this period. I think it does no harm to players and no one would mind if he needs to start new game after 5 minutes because you cant make much difference in that time and that way would be avoided 4v5 games from start.
Obviously there is not much matter considering gold after 5-th minute, so i dont mind leavers after 5-th minute, game can still be played normaly, but minimum 913 gold difference in 5-th minute per team player and i think it is at least 1.2k because of creeps farming, and 2 players mid spliting gold not 3. Latter that differnce becomes more and more worthless and if game lasts long enought 5 player team will take their player advantage to win (if you are lucky to have good team and to be vs not so good team). Latter game leavers dont make so much differnce in game as the early game leaver.
I still strongly support under 5 minutes leaver game aborts and lets play new one it is not problem to rejoin new game, and it could make playing exp much better for players not to farce them to play in 4v5 game from start.
I got another topic about laser tower mid that is total hendicap for laser tower team, laser tower is not needed in league games it supports noobs to outfarm their team mates while they face enemy 2v3 mid with only half of creeps that can get next to that tower to them. More here :
http://btanks.net/forum/viewtopic.php?f=48&t=4006
I do this to make game play better and more fun for players i know there are peopl winning in all kinds of situations but keep it real early leaver ruins game and it can get easily fixed. Thank you for reading, constructive comments welcome.