Being a Monk myself, it's very easy for me to spot a bad one in a PT. I also think that most people would say that Monk is the easiest to had bad players behind because a lot of people haven't partied with good Monks. Monks are rare enough post 60 when the real fights begin so what would people base their opinions of?
Below LV30 it's so easy for a bad player to play a Paladin or Warrior. As long as they keep their armor updated and spam provoke, you won't know if they will really be any good post 40. There is, however, a good way to spot the good Warrior tanks. Just see who manages to Berserk for skillchains and turn it off afterwards. Bad Paladins can probably make thir way to the 50's without people realizing their ineptitude because it is very easy for them to get into parties. Once the bad player PT's with a Ranger at 55 (Sidewinder), you'll know if he's really any good. I know of a very bad Paladin that got LV75. He's blacklisted by a lot of people as he is known to bail from PT's that get in trouble, refuse to provoke after dying accidentally once and be rude overall.
Bad players can also play WHM well once they get enough smarts to know that too many cures kill them. To spot the good ones, you look for those that know when to use Erase, who to Haste, who never let a status disability last for more than 5 seconds and those that participate in magic bursts.
Bad BLM are hard to spot once they get the timing of MB's down. The good ones know when to use Stun and Sleep.
Once DRG get 49 and Penta Thrust, it's hard to determine if they are any good. Once they get to the 60's it becomes easy to identify the good from the bad by their accuracy, how they take care of their wyvern, when they use their jump abilities and how they participate in hate control.
RDM are also easy to get by with since they are so in demand. Most people are happy with those that cast enfeebling spells, refresh, and BLM spells. Decent RDM know when to use convert, the good ones know how to use it in battle without getting killed. What will really make a good RDM stand out is when the PT gets in trouble. If the RDM knows how to use Stoneskin, Phalanx in tight spots, that RDM is good.
Prior to LV60, bad DRK can get by easily. Post 60 you'll know the good ones by their use of ABS spells and Stun, their aptitude with Thief SJ, their skill with Great Swords and their alternate set of defensive armor.
Bad players can play Samurai easily before LV30 since most people don't know that Samurai at that time ought to be part-archers for TP gain and accuracy. The good ones pre 30 will be equipped for tanking. The good ones post 30 will decide all the skillchains and be able to do at least 2 skillchains a fight against IT monsters. At the 40's up, you'll be able to identify good Samurai even better by their ability to alternate between accuracy/attack equipment and defense equipment.
BST is probably the easiest job for a bad player to hide in since there isn't any other person to see them foul up. However, it's almost guaranteed that only the good BSTs get past the 50's.
Bad THF can get by once they know how to macro Sneak Attack + Trick Attack. It's not very hard. You will be able to spot the good ones at how quickly they set up the initial fuidama and how they will be able to do another fuidama 10 seconds after that one. Incidentally, you can spot any bad sub-tank/attacker job easily when they are PT'd with Thieves because they do not line up properly and they don't switch to defensive armor when they get monster attention.
I think the jobs where bad and good players can be immediately noticed are Ninja by their aptitude at hate control, utsusemi, debuffs; Ranger by their skill at soloing worm-types; Bard and Summoner at how and when they uses their songs and summons.
Edited, Wed May 19 21:49:21 2004 by Resistance
Do the best with the things you have before thinking that you need expensive gear. The only real requirement is equipment that makes sense.
EXP in FFXI is easy when a party works together properly.
Read:The only true legend in FFXI
Guides: Monk Tactics 101: Levels 14-18