I see this a lot on these forums; people saying stuff like 'you're not a real lvl 32 unless your Grimoire is 2500+' or 'I just checked this guy's stats, and his k/d is only 1.1'. Then you get retorts saying 'that means nothing, the only true way to tell if someone is good is...' The fact is, there is no one stat that can adequately describe a player's skill level. That is because 'skill' comes in many different forms, and also for any given stat, there are ways that it can be artificially inflated to make the player seem better than they are. Examples: Crucible k/d: For a start, many players only do PvE and rarely bother with Crucible. However, even those that do play can get a decent k/d using 'unskilled' tactics. Camping in corners with shotguns or fusion rifles perhaps, or lurking invisible on the edges of the map and getting the occasional lucky snipe. Players that do this will have a decent k/d, but they are not exactly 'skilled' nor are they a great asset to the team. Similarly, in Control, someone can capture a lot of zones, or maybe focus on zone defence. They are playing in a 'skilled' way, but their k/d won't reflect that. Crucible wins/losses: As I'm sure many people are frustratingly familiar with, sometimes you just get put on crap teams and no amount of carrying will be enough. The best players can be let down by awful teamates, and apparently are with alarming regularity. Similarly, a noob can get lucky and be paired with good players that will carry them to victory despite them underperforming. Level: Since 31 is attainable with vendor gear, anyone can get there given enough time. 32 required raid gear, but that can be attained wither through being carried or cheesing, meaning that 'unskilled' players can still acquire what they need, especially if they are lucky with drops. Raid completions: As above; bad players can be carried or cheese, or join in right before the end. Grimoire: This will naturally increase over time as you simply get more and more kills on mobs with various types of weapon. Also, it can be boosted significantly by simply following Youtube videos to find all the collectibles. Maxed weapons/armour: At the time of inspection, you cannot be sure if someone is using the best gear they have, or if they are in the process of levelling up new stuff. My point is that none of these stats are reliable indicators of skill on their. The only true way to judge someone's ability (other than actually playing with them) is to look at their profile as a whole. Skilled players will tend to be pretty good in most areas, and even if someone's k/d is sub-par, their other stats may make up for it. I would say the most reliable single stat is actually simply time played. That is no guarantee, but in general, the more practice you get at something the better you will become. Just my two cents.