Man in a Panama Hatby
chaliceComment by Artyste: Greetings from the Critique Club. My critiques are generally geared towards trying to help you improve your score within DPC, and not on any true "artistic" merit of the photograph itself, unless it relates to DPC voters and scoring. Please keep that in mind as you read this.
Initial Thoughts
This isn't bad. Lighting is a little too hard, and you seem to be on the wrong side of the frame.
Composition/Content
In classic portraiture composition, it's best if you leave negative space to the side of where the subject is a)looking, or b)leaning. This gives the viewer an impression of flow, and it's difficult to pull it off if you decide to break from this. In this photo, you just seem to be going against the flow for no real reason, and as such leave the viewer (me, in this case), feeling crowded out. I end up looking more at the space than at you.
Background
Backround is good, and I like the soft gradiating from dark to not so dark.
Camera Work/Technical
You lack a touch of focus in the key area, which is just around the eyes. Also, your choice of a longer exposure (1.6 seconds) has resulted in a bit of motion blur in the eyes (and other areas) as well, contributing to the focal problem. In portraiture, it is very important that the eyes (if you are using them), are sharp and appealing to the viewer. If they lack focus or sharpness (unless for some express desired intent, which I don't feel here), you tend to lose the viewer. What I would suggest, if you wished your portrait to retain the ambient lighting, is to bump up to ISO 800 (which the 20D can handle very well), and drop the aperature to 3.5 or 4, thus giving you more shutter speed to work with, and probably sharpening your eyes much better. Now granted, the usual voter won't notice something like this *conciously*, but I can guarantee that it'll be a factor to many, even if they can't quite say why.
Digital Processing
Well, I don't know if you wanted the tungsten/ambient lighting this way purposely or not. It does add a little bit of a warmer, saddish aspect, but voters generally don't do well with it, and less yellow and more natural skin tones might have helped your voting. Your contrast is nice though, but it could still use another couple of low-pass USM for sharpening.
Fits the Challenge
Unless this isn't you, it fits the challenge.. obviously.
My Opinion of the Photo
While I liked it on first glance ok, I do think it would have been a stronger photo had you been on the right side of the frame. It would have given the impression of having more space and feeling less cramped. As DanSig pointed out, there are reasons why most portraiture "rules" are in place, and choosing to go outside those rules should have a strong and intensive purpose. I don't feel that your photo really had these, so it showed in the voting.
Good luck in future challenges.