Arpad Elo (1903-1992) was a physics professor and created the rating system. This YouTube video demonstrates correct pronunciation of his name: http://youtu.be/Y6hrljjvK6A
correct way to pronounce ELO as in the rating system?

It's, to be technical Élő, because Árpád was hungarian, the English language just doesn't have umlauts.
So good luck with that.
But without the umlauts, it's either ee-loh, or eh-loh (silent h in both).
Why can't we input letters from the actual phonetic alphabet?
I can't find it anywhere as a feature.

I knew that it was named after Arpad Elo and @GnrfFrtzl I didn't think an umlaut would be in Arpad Elo's name or the rating system because I always thought the umlaut was the U with 2 dots above like this Ü

... should you pronounce it should it be E-L-O saying each letter as a letter...
Definitely not, that has an altogether different meaning:
https://www.youtube.com/watch?v=98P-gu_vMRc

I knew that it was named after Arpad Elo and @GnrfFrtzl I didn't think an umlaut would be in Arpad Elo's name or the rating system because I always thought the umlaut was the U with 2 dots above like this Ü
Well, you're right, I thought these was called 'umlauts' in English in general, but these are really called 'acutes' and part of what's called 'diacritic'.
The more I learn each day.

I knew that it was named after Arpad Elo and @GnrfFrtzl I didn't think an umlaut would be in Arpad Elo's name or the rating system because I always thought the umlaut was the U with 2 dots above like this Ü
Well, you're right, I thought these was called 'umlauts' in English in general, but these are really called 'acutes' and part of what's called 'diacritic'.
The more I learn each day.
I always called the umlauts for any (edit: only a,o and u) vowels (after taking German) and Wikipedia seems to agree.
http://en.wikipedia.org/wiki/Diaeresis_%28diacritic%29

I knew that it was named after Arpad Elo and @GnrfFrtzl I didn't think an umlaut would be in Arpad Elo's name or the rating system because I always thought the umlaut was the U with 2 dots above like this Ü
Well, you're right, I thought these was called 'umlauts' in English in general, but these are really called 'acutes' and part of what's called 'diacritic'.
The more I learn each day.
In Élő there is an acute accent over the E and an umlaut over the o. All such marks are called diacritics.
When German names are translated to English, an e is often added to substitute for English's non-use of umlauts. Loewenthal, for example. The oe replaces an o umlaut.
I'm not certain whether this practice of anglicization affects Hungarian names.

I knew that it was named after Arpad Elo and @GnrfFrtzl I didn't think an umlaut would be in Arpad Elo's name or the rating system because I always thought the umlaut was the U with 2 dots above like this Ü
Well, you're right, I thought these was called 'umlauts' in English in general, but these are really called 'acutes' and part of what's called 'diacritic'.
The more I learn each day.
In Élő there is an acute accent over the E and an umlaut over the o. All such marks are called diacritics.
When German names are translated to English, an e is often added to substitute for English's non-use of umlauts. Loewenthal, for example. The oe replaces an o umlaut.
I'm not certain whether this practice of anglicization affects Hungarian names.
I know their hungarian names (the diacritics that is), I was just not aware how these are called in English.
Most angilicization of hungarian names is simply leaving the acutes and umlauts out, like Elo as a perfect example, but I've also seen some where they added completely unneccessary letters, like 'Judith', which is simply 'Judit' in hungarian, without a stress on the end.
I've also seen some literal translation of names (Zsuzsanna - Susan), which just doesn't make a whole lot of sense at all.
Just out of curiosity how should you pronounce it should it be E-L-O saying each letter as a letter, ELO like ee-low or like hello without the H?