Hungary’s 2022 election resulted in an overwhelming victory for the incumbent Fidesz party, led by Prime Minister Viktor Orban, against a broad opposition coalition, led by Peter Marki-Zay, comprised of liberals, social democrats and the nationalist Jobbik party. Orban’s twelve-year-long government has been the focus of international attention over its nationalist policies and weakening of democratic institutions.
One of the earliest initiatives of Orban’s government was a set of amendments to the electoral law in 2011. While Hungary retained a mixed-member system, the three-tier system introduced in 1989 was replaced with a two-tier system. The size of the legislature was cut drastically, from 386 to 199. This involved a redrawing of the single-seat districts, as the number of these districts fell from 176 to 106: the two-round system previously used for these seats was replaced by first-past-the-post.
The process of drawing new electoral boundaries and introducing a new electoral system represents an excellent opportunity for a governing political party to entrench its own advantages. Fidesz had a completely free hand in that process, owing to its two-thirds constitutional majority. So, what does the electoral system look like?

Based on the 2022 results, there is a clear negative relationship between Fidesz vote share and registration numbers. Interestingly, this is driven by very high registration in the electoral districts of suburban Pest county, which is the cluster on the right of the plot: Budapest, the opposition’s stronghold, has roughly average enrolment.
But what does this mean in terms of actual election results? In order to examine this, I simulated a set of uniform swings1 between Fidesz and the Alliance for Hungary. The below plot shows seat totals in the single-seat districts at different vote shares for both the opposition alliance and Fidesz (vote shares for the other parties were kept constant).

The vertical line shows where the two parties tie – approximately 44% of the vote each, or a swing of 7.8% towards the opposition. At this level, Fidesz would win 56 single-seat districts to 50 in total for the opposition. In order to win a majority of the single-seat districts, the Alliance would need approximately 46% of the vote to 43% for Fidesz.
Of course, the list seats need to be taken into account. The below plot shows the number of total seats each party would have won with the same vote shares as in the prior plot. The vote share for the other parties is held constant, and I assume that the nationalist My Homeland party would have held onto its 5% of the vote and 6 seats, and that the German minority would have elected its single member under the special procedure for ethnic minority parties.

The effect of the list seats is fairly minor. A tied vote would give the Alliance 91 seats to 100 for Fidesz, the slimmest of absolute majorities. Fidesz loses this majority at a fractionally lower share of the vote. However, for the opposition to win a plurality, they need about the same 46-43 vote share as they need for a majority of the single-seat districts, and to win the 100 seats required for an absolute majority they need 47% of the vote to 42% for Fidesz.
How serious is this effect? How does it compare to other jurisdictions? One method which has received some use in the (inevitably US-centric) gerrymandering literature is the ‘efficiency gap’, which calculates the difference between the number of wasted votes for the two major parties, as a proportion of all votes. I calculate the efficiency gap at this election to be 5.2%, again ignoring votes for minor parties. According to the paper laying out the efficiency gap measure, this gives Hungary a map roughly as biased towards Fidesz as the maps in Minnesota or South Carolina were towards the Republican Party, or the map of California was towards the Democratic Party. Hungarian bias, however, does not seem to be as strong as that in North Carolina or Florida.
Hungary’s 2012 electoral map, then, provides Fidesz with a modest but meaningful electoral advantage, only slightly ameliorated by the list tier. Nonetheless, the opposition at this election achieved a vote share well short of what would be needed to win a majority. Unlike in Poland, the role of the electoral system in the installation of this government has been seemingly fairly minimal.
1 Note that ‘swing’ is here defined as percentage points subtracted from Fidesz’s (or the opposition alliance’s) vote and added to the opposition alliance’s (or Fidesz’s) vote share. I believe this is the Australian definition, as opposed to a British one that (I think) averages the two figures.