Intraparty Preference voting (IPV) systems offer different incentives for candidates to cultivate a personal vote, but little is known about how the policy positions of candidates affect their success in intraparty competition. This article analyses the effect of ideological positions and personal attributes of candidates on their electoral success in the Swiss Lower House election of 2019. We use candidate survey data to test three propositions. First, that under a IPV system with multiple preference voting candidates positioning themselves ideologically closer to their party position  are more successful than their co-partisans deviating from the party median position.  Second, that the ideological position of candidates have a weaker effect on their electoral outcomes than their personal attributes. Additionally, open lists are more complex electoral environments for voters as district magnitude. Therefore,  as our third proposition we test whether the ideological positions of candidates have a weaker effect on their electoral success , as constituency magnitude or the number of co-partisan candidates  competing increases in their district.