It's pumping a ton of Javascript out in terms of libraries. From a web design perspective, I'm absolutely in love with it. Making a site like that look great while still responsive and mobile friendly isn't easy at all if you don't do it right, and I say that having done some pretty trick OS work. I respect the hell out of good web developers who do stuff like this because for all of my experience and skills as a Software Engineer, web design is my weakest area. You have to have the eye for it, and I think what makes me skilled with the hard stuff takes away all of the skills necessary to really make things look good. Props to ESPN for really pushing stuff like this out in terms of presentation.

That said, they are, again, pumping a lot of JS out in execution. Just skimming, I noticed Skrollr being used, which is a library to make parallax scrolling work, and I don't even need to look further to tell you that's one of a bunch of JS libraries in the mix. Normally, this isn't an issue because JS works on pretty much every modern browser, and it gets faster every day, which explains the sudden jump in the quality and functionality on a lot of sites. The problem is that it requires power, and mobile device battery life is precious. So, mobile devices really limit Javascript execution as much as possible, including while doing things like scrolling. iOS actually completely tries to stop it, which is a problem on a site using a JS library for prettier scrolling. So, Skrollr actually disables scrolling completely and uses workarounds to mimic it. So, that alone would create an issue for some people on mobile devices along with a plethora of compatibility issues and bugs.

This has nothing to do with the article obviously. I just enjoy these things a lot, and I figured it'd at least be semi-interesting and informational to explain why you probably had some problems. Basically, it's not you or your phone. It's bad software design.