Read this it should clarify things:

"There were two coin tosses in Des Moines and four more in Ames, Newton, West Branch and Davenport, the Des Moines Register reported. Clinton won all of these.

Another video, which the Des Moines Register did not report on, also emerged, showing a seventh coin toss in Johnson County. Sanders won what appears to be just this one.

Clinton reportedly won six out of the seven coin tosses. This assured her several more delegates to the Democratic Party’s county conventions, of which there are thousands that are selected from the state’s 1,681 precincts in order to determine who gets statewide delegate equivalents.

Clinton ultimately got 700.59 state delegate equivalents, while Sanders got 696.82 state delegate equivalents, a mere 3.77 point difference, according to the Iowa Democratic Party.

In other words, although six is a small fraction of the thousands of overall county delegates, these coin tosses — all of which Clinton reportedly won, despite the low probability — may have pushed her over the edge, giving her the extra statewide delegate equivalents that granted her an additional Iowa delegate.

Clinton ended up getting just one more Iowa delegate, with 22 to Sanders’ 21."

Source - http://www.salon.com/2016/02/02/critics_cry_foul_over_coingate_hillary_clinton_had_1_6_chance_of_winning_6_coin_tosses_that_made_her_winner_in_iowa/