For those cursed with lag-- or those looking to create havok with the rankings, annoy their fellow players, and risk the ire of Bungie by performing the standby cheat-- the Head to Head playlist is for you.

If your Internet connection is not quite as low-latency as that of your opponents, you're going to eventually notice it. One-hit-kill weapons will be difficult for you to use effectively, as the shots you appear to have made first will actually occur after your opponents, leading to many failed shotgun, sword, rocket and melee attacks. Your best bet will be weapons that take longer to kill if you can be more consistent and accurate than your prey, with weapons like the SMG, the battle rifle, and the carbine. And if you can stand the annoying delay, with proper timing area effect weapons like grenades are also useful.

But sometimes you'd like to play a game just for once without lag; if so, the Head to Head playlist is for you.

Since Halo 2 on Xbox Live does not use an authoritative dedicated server, but actually hosts games on clients' Xbox consoles, one player in the game has to be running the "server" in the client/server networking model. This player in essence experiences no lag and is able to do certain things that other players can't because of this. (No, I am not going to go into what things. Quit trying to cheat.)

If your Internet connection isn't the best, or if you're matched up against foreign players, chances are you won't be made the host. I don't know how Xbox Live determines who hosts games, but I do know that the system's records of your past network performance figures into it. I think I can confidently say that I've never hosted a Team Slayer, a Rumble Pit, or other medium to large team game. It simply hasn't ever happened.

However, unless your connection is the worst in the world, chances are that in a Head to Head game, with only two players, you might get chosen to host the game. After all, the latency between any two points as measured by the simple ping test is simply a number. Without running a complete traceroute, there's no way for Xbox Live to really determine where that latency is coming from, and which of the two players' networks is responsible for it. Since Xbox Live doesn't host games itself, the network performance between each of the two client machines and the Xbox Live servers is largely irrelevant, as all that connection is used for is reporting and messaging. So the fact that one player lives right next door to his cable company and has a ping of 50 milliseconds, while another player has a ping of 200 milliseconds, really doesn't matter. Of the two players, the one hosting the game will experience no real lag at all, while the other will get the full value of whatever latency of the combined connections between his Xbox and the other player's. So if the first player's ping to his ISP's router is 50ms, and the second player's ping to his ISP's router is 200ms, and the two ISPs involved have an imaginary, theoretical peer connection between them that has no latency whatsoever, then the host will have a lag of 0 milliseconds while the other player experiences 250ms of lag-- regardless of whether the host is the first or second player! The host could be player 2, with a lag of 200ms between him and his ISP's router, but if he is the host, he won't see any lag-- the player with the good connection will get all of it.

This means if you've ever wondered what it's like to have a Halo 2 shotgun that works, to see grenades actually leave your hands at the same moment you throw them, to feel the crunch as a melee attack impacts an opponent and actually kills him, try the Head to Head playlist. Unless you're playing on a wireless router connected by dialup to a mom & pop ISP in somebody's basement, you've probably got a good shot at being host at least some of the time.

You may be accused of cheating. If you aren't, don't sweat it. A smart person with access to logs can tell the difference between a connection that is relatively high latency, but is still reliable and not being tampered with and someone attempting to sever the network connection at opportune moments while hosting a game and thus gain an advantage by this-- in other words, standbying. In fact, in the Head to Head playlist, this happened to mean in a game of Ball Duel on Foundation the other day. Whenever I shot at the other player, his body would begin walking in place against a wall and did not react when shot or meleed. Then the "reconnecting to session" screen would appear. When the game reconnected, I was dead and the other player was calmly walking away. This happened no less than three times until he won the game.

I left feedback on his account through Xbox Live, and this morning I notice that in the Head to Head playlist next to his gamertag it says "no games played" and there is no rank-- at the time the game was played, he was a 15. His other ranks are untouched-- I can only hope that more aggressive punishments are in the works, because I can hardly imagine that a player standbys in some playlists but not others.

You may find that advancing rank in the Head to Head playlist is easier than in some other lists without employing any methods of cheating at all, however. While Bungie does revel in a wide variety of gametypes, it does seem as if the majority of players of Halo 2 prefer their shooters as straight-up slayer. They clamored for a Team Slayer only playlist and got it.

However, the Head to Head list does contain slayer games as well as other games-- oddball and hill games, as obviously flag and assault games don't work well with two players. You may find that players will quit out immediately once the game loads if the game turns out to be a non-slayer variation. Some seem more than willing to take the occasional hit to their rank by quitting a game in order to get a gametype they feel more confident in.

Others, it seems, especially those with lower ranks, don't seem to understand the different gametypes and just continue to play slayer regardless. They may be slaughtering you in terms of kills, but be neglecting to accumulate any hill control or oddball time, leaving you to rack up a pyrrhic victory.

In my recent tour of the Head to Head playlist, I'd say slightly less than half of the games were non-slayer variations. Of those games, in about half of them the opponent quit before the game was over. Of the opponents who quit, about half of them quit immediately as the game began; the other half after I'd gained an insurmountable lead-- usually because they weren't actually playing appropriately for the gametype. I'd expect this kind of play would happen less at higher rank levels, but with players ranked 20 or less it still seems commonplace.