Create a World Cup guessing program
Python 2.x  - 368 283

Interesting challenge. Of course we need to get present rankings from the FIFA.
Brazil have the so-called "12th man" as they have home advantage therefore the weighting 12/11. 

a='BRA CHI COL URU FRA NGA ALG GER MEX NED CRC GRE ARG SUI BEL USA'.split()
d=[1242*12/11,1026,1137,1147,913,640,858,1300,882,981,762,1064,1175,1149,1074,1035]
m={}
for n in[16,8,4,2]:
 j=0
 for k in range(0,n,2):
  s=a[k] if d[k]&gt;d[k+1] else a[k+1]
  m[a[k]+' '+a[k+1]]=s
  a[j]=s    
  j+=1
def f(s): 
 try: print m[s] 
 except: print 'no result'   


Tips to shorten the above are welcome :-). 

Improvements thanks to @TheRare and @MrLemon

a='BRA CHI COL URU FRA NGA ALG GER MEX NED CRC GRE ARG SUI BEL USA'.split()
d=15,6,10,11,4,0,2,14,3,5,1,8,13,12,9,7
m={}
for n in 16,8,4,2:
 j=0
 for k in range(0,n,2):s=a[k]if d[k]&gt;d[k+1]else a[k+1];m[a[k]+' '+a[k+1]]=s;a[j]=s;j+=1     
def f(s):print s in m and m[s]or'no result'


This leads to the following results: 

BRA CHI: BRA
COL URU: URU
FRA NGA: FRA
ALG GER: GER
MEX NED: NED
CRC GRE: GRE
ARG SUI: ARG
BEL USA: BEL
------------
BRA URU: BRA
FRA GER: GER
NED GRE: GRE
ARG BEL: ARG
------------
BRA GER: BRA
GRE ARG: ARG
------------
BRA ARG: BRA


Example calls: 

f('BRA MEX')
no result
f('BRA CHI')
BRA