Ok since Genesis is banning neutral starts, I wanna know what port (besides 1) you guys would choose to get the best spawn points on each stage. Assume that you're not gonna switch ports inbetween games.
It's not banning neutral start; you still always have to honour a request for one. It's banning implementing a neutral start by manually moving to neutral positions at the start of the game, and forcing it to be done by choosing the ports which spawn in neutral positions.
Spawn points and stuff vary by stage, but I feel that 3 would be the best. Honestly, though, I feel you should just switch as necessary if you really want the neutral start.
I also got the impression that port 3 was good, I think heavily due to the stupid spawning position it gives against port 1 on FD. Overall though it's not so great.
These are pictures of the spawning positions for each port/stage combination:
http://imgur.com/a/QYBbX
All ports come with problems; a given port will have an advantage against another given port on some stages and a disadvantage on others. Because of this, you can't say which port is best without seeing which port your opponent has chosen or having an idea of which stages will be played on, preferably both.
I'd suggest aiming to choose your port after the opponent to get the appropriate port counterpick and calling for a neutral start if you can't do so. Alternatively, you could aim to secure port 1 (which also has the advantage of guaranteeing you port priority) and call for neutral start if your opponent chooses port 3 or 4; you could even go so far as to not call for the neutral start until you end up going to a stage where you'd spawn unfavourably, sticking with the normal spawning positions if you start in a neutral or advantageous position. Since port 2 has no advantageous spawns against port 1, if you have port 1 then you definitely don't want to neutral start against port 2. Ports 3 and 4 have some advantageous and some disadvantageous spawns against port 1, which is a tradeoff you may or may not want. Of course, if your opponent calls for neutral start then any kind of port selection metagame becomes moot, outside of securing port priority (which is another reason to choose port 1, assuming you don't want the reverse port priority for throws instead).
Below are tables of the distribution of neutral, advantageous, and disadvantageous spawning positions.
For the purposes of these tables, a spawn is "disadvantageous" when it's above another spawn, unless the spawns are on opposite sides of the stage (even if one of them is on a platform or closer to centre stage), in which case it's considered "neutral"; for example: port 1 vs port 3 on Stadium is considered neutral rather than disadvantageous. It's not entirely clear-cut whether some spawn are advantageous or disadvantageous, especially taking different characters into account. For example, in port 1 vs port 4 and port 2 vs port 3 on Stadium, the player on the ground has the advantage of being beneath the opponent but the disadvantage of being against the ledge. If the player on the platform can put out a threatening option from that position (the most extreme example probably being a Shine from Fox) or the player on the ground can threaten/control the platform well, then it forces both players to commit immediately; if both are true then the risk and reward is high for both players.
By Stage
Yoshi's Story
|Port 1|Port 2|Port 3|Port 4
Port 1|X|Neutral|Advantageous|Disadvantageous
Port 2|Neutral|X|Advantageous|Disadvantageous
Port 3|Disadvantageous|Disadvantageous|X|Disadvantageous
Port 4|Advantageous|Advantageous|Advantageous|X
Fountain of Dreams
|Port 1|Port 2|Port 3|Port 4
Port 1|X|Neutral|Disadvantageous|Advantageous
Port 2|Neutral|X|Disadvantageous|Advantageous
Port 3|Advantageous|Advantageous|X|Advantageous
Port 4|Disadvantageous|Disadvantageous|Disadvantageous|X
Pokémon Stadium
|Port 1|Port 2|Port 3|Port 4
Port 1|X|Neutral|Neutral|Disadvantageous
Port 2|Neutral|X|Disadvantageous|Neutral
Port 3|Neutral|Advantageous|X|Neutral
Port 4|Advantageous|Neutral|Neutral|X
Battlefield
|Port 1|Port 2|Port 3|Port 4
Port 1|X|Advantageous|Advantageous|Advantageous
Port 2|Disadvantageous|X|Disadvantageous|Disadvantageous
Port 3|Disadvantageous|Advantageous|X|Neutral
Port 4|Disadvantageous|Advantageous|Neutral|X
Dream Land 64
|Port 1|Port 2|Port 3|Port 4
Port 1|X|Advantageous|Advantageous|Advantageous
Port 2|Disadvantageous|X|Advantageous|Neutral
Port 3|Disadvantageous|Disadvantageous|X|Disadvantageous
Port 4|Disadvantageous|Neutral|Advantageous|X
Final Destination
|Port 1|Port 2|Port 3|Port 4
Port 1|X|Neutral|Disadvantageous|Neutral
Port 2|Neutral|X|Neutral|Disadvantageous
Port 3|Advantageous|Neutral|X|Neutral
Port 4|Neutral|Advantageous|Neutral|X
Totals
Overall
Port|Total neutral spawns|Total advantageous spawns|Total disadvantageous spawns
Port 1|6|8|4
Port 2|7|3|8
Port 3|5|6|7
Port 4|6|7|5
Versus Port 1
Port|Total neutral spawns|Total advantageous spawns|Total disadvantageous spawns
Port 1|X|X|X
Port 2|4|0|2
Port 3|1|2|3
Port 4|1|2|3
Versus Port 2
Port|Total neutral spawns|Total advantageous spawns|Total disadvantageous spawns
Port 1|4|2|0
Port 2|X|X|X
Port 3|1|3|2
Port 4|2|3|1
Versus Port 3
Port|Total neutral spawns|Total advantageous spawns|Total disadvantageous spawns
Port 1|1|3|2
Port 2|1|2|3
Port 3|X|X|X
Port 4|3|2|1
Versus Port 4
Port|Total neutral spawns|Total advantageous spawns|Total disadvantageous spawns
Port 1|1|3|2
Port 2|2|1|3
Port 3|3|1|2
Port 4|X|X|X
Port 3 has an extremely advantageous position against port 1 on FD (trapping them at the ledge), as does port 4 against port 2.
I'd say port 1 is the best port, overall. It generally has neutral or advantageous spawns, with few disadvantageous ones (partially due to never spawning on the top platform). It is never disadvantageous against port 2; unless you value having more advantageous spawns over having no disadvantageous spawns, you should use port 1 against port 2. Port 1 vs port 2 is the only port combination for which one of the ports (port 1) has no disadvantageous spawning positions on any stages.
Port 2 is generally bad against everything, except arguably port 1 (which it's always worse than or neutral with, meaning there's no reason not to call for neutral start as port 2 vs port 1). Ports 3 and 4 have two more advantageous spawns against port 1 than port 2 does at the cost of also having one additional disadvantageous spawn. I'd say you should just always call for neutral start against port 1, unless you want to go for the cheese on FD/Stadium with port 3/port 4 at the cost of having the worse spawning positions on other stages.
Both port 4 vs port 2 and port 3 vs port 4 have only one stage with a disadvantageous spawning position (Fountain of Dreams and Dream Land 64 respectively), so if you can ban that stage or if you know you won't play on it then you should choose that port combination.