I routinely ride alone.

The pack scares the living bejeezus out of me, so I hang back and start after they're all gone.

If it's later in the season and I'm fairly well conditioned by then, I'll overtake a fair number of the laggards. Usually I catch up to the main body by lunch, or at least not more than one stop behind them by then.

If it's early in the season or I'm NOT fairly well conditioned, I start at the back and stay there. On occasion I've been the last or next to the last coming in. On one occassion I was riding with someone who was even slower than me. The SAG finally took her in but I opted to ride the rest of the way in on my own - SAG was packing it up and they tried to talk me out of it, but the only reason I was THAT far behind was the person I rode with.

I did that last leg actually faster than any other, simply because I wasn't hanging back waiting for her. I decided after that that I do better on my own, not to be slowed down by a partner, and not slowing a partner down. I MUCH prefer to ride at my own pace. I can ride almost forever if I can go at my own pace.