Hmmm dunno if I could do that solo, but you could always link up with the people right next to you.
I travel and vacation alone, so I ALWAYS meet new people. I'm pretty outgoing and talkative so it's not hard, networking is something I grew up on living in north hollywood, so in fact I prefer to go solo most places where I want to MEET people.
IF I go to the bar alone I will 100% meet people and more women. ALWAYS. I do have my crew here I meet up with of course, but we stay in our 10 deep crew and nobody really sprawls off. 2 sets (2 women sharing an evening) will most likely not want to get involved in a group of men and women that large, esp since women (the ones in the group) may get territorial. What I usually do is chill with the crew, then by 1am, they head over to the dance club since clubs end at 5am here, I hang back for an hour or 2, by then everyone in the bar is buzzin, the older crowd my age is still lingering. I'm always hit up by 2 sets "hey can we sit here, or where are your friends? you here alone?"
From my years alone, I've learned humans are very social beings, it's instinct to stay in packs for survival, communication and various reasons. With that said, it is unusual to see a rogue human, so packs are curious about you, far less threatened and more acceptable (unless you look like a crack head or some shyt) into pulling you into their pack, it raises their numbers, security and communication, more people, more conversation. I get approached every single time. I guess I never understood why you'd want to go to a bar (to meet NEW people) with more than 1 other person, it cuts the odds dramatically.
As for sporting event, never done it, I can't see it working mostly because people are there to focus on a game, not socialize or meet new people. but like I said, you could always just link up with the people sitting next to you on either side. you're alone and thus non-threatening.