Did you ask this "4 year old" why they played 25...Kf8?
4 year old chess player

@tigerprowl9 Yeah it wasn't required but he is 4 year what else we can expect? some time, may get intimidated by good player...he thought he would get checkmate...

if anybody have the uscf or fide tournament experience please just have guess about his rating...it would help us for his future tournaments..
If this game is really played by a 4 year old.Then definitely he has got real potential to be a very strong chess player in time to come.As tigerprowl9 asked why he played kf8 could have got him mated very fast.But please continue teaching him.

If I had to guess? Probably about 1000, maybe 900, which is pretty amazing for a four-year-old. Keep working with him.
Thanks guys..We have registered him for uscf now and tomarrow is his first uscf rated tournament.
Please post his notations here tomorrow win or loose.I look forward in seeing his games :)

Sure, basically on 3rd april 2015 he played 3 games with 12,11,10 year old opponents and won all of them. You can refer them below :
https://www.youtube.com/watch?v=cg9Lnc7Tj5c
https://www.youtube.com/watch?v=E-Lt1GzRrLM
Very impressive there is no doubt your kid has a very bright future.Can you imagine what he will be like in 2 years?

Not sure but We focusing on basics more..to build his foundation of tatics and strategy. I can imagine of rating around 1500 to 1600. But in US we are not getting much opportunity to play at club. I searched for club where weekly internal tournament will happen. Because he has to play more to improve. on 25th april we are going for 2015 PA State Amateur Championship let see how it goes..!

dineshrpatil2013, do you know about chesskid.com? If he doesn't have many opportunities to play, that might just be great for him to play on. You might even consider letting him use chess.com, with your supervision of course. Heck, I'm fifteen with a C-rating and I'd like to play this kid, if possible.

@NewArdweaden Thanks.
By any chance does anybody know how to register for FIDE. he would come under India fide but not sure how to proceed for online registration.
Guys what you think, What would be the rating of this 4 year kid?