How far the candidates had any serious hope of competing against Putin is doubtful. Several stood against him, not just one. Pavel Grudinin came second with 11%, a poor second given than Putin gained more than 70% of the vote.
This may well have been because the main rival Navalny was barred from competing! Vladimir Zhirinovsky was another candidate, third, and Ksenia Sobachak with less than 2% but at least she spoke out against Putin which none of the other (non-barred) contestants dared to do. Who can blame them, given Russian responses to opposition!
There were actually seven other names on the Russian ballot during the 2018 Russian election even though everyone knew Putin would be elected for his second consecutive and fourth term as president. The three more important candidates were: Pavel Grudinin, Vladimir Zhirinovsky, and Ksenia Sobachak.
Grudinin argued he was a “model for how post-Soviet Russia should be run” because he successfully “privatized a state-run strawberry company and converted it into a profitable agricultural enterprise.” Zhirinovsky won 6% of the vote in Russia’s 2012 election but by 2018, he was 71 years old. Sobachak is a female journalist and former reality-TV star. Alexei Navalny, Putin’s most outspoken critic, was disqualified before the election.