I know it may not be fair to use these results (teams playing in different leagues, bad timing, teams not playing their best lineups/not taking competition seriously) but here is how the playoff teams did in this recent international window
League A Playoffs
Iceland vs. Romania...Iceland apparently were missing five standard players (according to ESPN commentary), they almost held England to a draw parking the bus while they were hammered in Belgium, though they are completely out of their depth in the top league, also if they cannot play with fans that will hurt them very much. Romania had a mixed week, they had a disappointing home draw to Northern Ireland but did beat Austria away which will give them confidence
Bulgaria vs. Hungary...Bulgaria twice dropped points in the final minute, a 1:1 draw with Ireland and a 1:0 loss at Wales, very fortunate to even have a chance to still make Euros. Hungary had an impressive win in Turkey but followed that up with a 3:2 loss at home to Russia. Bit of a Jekyll and Hyde side, they have some good attacking players but shaky defensively
League B Playoffs
Bosnia-Herzegovina vs. N. Ireland...Bosnia got an impressive draw in Italy but lost at home to Poland, another team which will very much be effected should there be no fans. Northern Ireland got a last minute draw in Romania but were hammered 5:1 at home to Norway
Slovakia vs. Rep of Ireland....both teams had a poor week, Slovakia were crushed at home by the Czechs and only managed a draw in Israel, Ireland too lost their home match to Finland and grabbed a late point in Bulgaria, neither side I think are favorites in the final unless NIR win it
League C Playoffs
Scotland vs. Israel...interestingly these two played in Glasgow, match ended 1:1. Scotland got a a win against a Czech C team but apparently were outplayed, Israel followed up their draw in Glasgow with a point at home to Slovakia. These two teams also met in the last Nations League with both teams winning their home games, so expect a tight match
Norway vs. Serbia...Norway lost at home to Austria but made up for it with a impressive 5:1 win away to N. Ireland, Serbia were poor, losing to Russia and then playing a scoreless draw at home to Turkey where they were outplayed. Norway is probably actually the favorites in this, lets see if they can handle that pressure with an impressive core of young players coming through
League D Playoffs
Georgia vs. Belarus...Georgia won in Estonia but then played a draw at home to potential finals opponent Macedonia, Belarus won away to Kazakhstan but lost at home to Albania
Macedonia vs. Kosovo...Macedonia beat Armenia and drew at Georgia while Kosovo, who were riding some momentum pre-Covid, had a poor week only picking up a point in games against Moldova and Greece
