dead reckoning
guessing
shot
guess
guesswork
guesstimate
rule of succession
guesstimation
underrating
maravedi
underestimation
underestimate
underreckoning
lowball
farthing
undermeasure
micromethod
subohm
extrapolate
interpolate
superstatistic
shot in the dark
smell of an oily rag
underfit
microcensus
misestimate
WAG
median
gauge
little
statistically
small
enough to put in one's eye
minimum
halfpennyworth
misestimation
submarginal
drop in the ocean
drop in the sea
distribution-free
microanalysis
paucity
drop in the pond
underbet
spit in the ocean
margin of error
underprediction
underorder
fat chance
prediction