| Ratings 
 
 
  | Year | Rank | Edo | Dev. | Games |  
  | 1929 | 668 | 2175 | (78) | 14 |  
  | 1930 | 762 | 2159 | (82) | 0 |  
  | 1931 | 888 | 2143 | (84) | 0 |  
  | 1932 | 977 | 2128 | (86) | 0 |  
  | 1933 | 1062 | 2112 | (85) | 0 |  
  | 1934 | 1150 | 2096 | (84) | 0 |  
  | 1935 | 1269 | 2081 | (81) | 24 |  
 
Rating table notes
 | 
| Biographical data |  | 
   | Name: Karu, Arnold |  
   | Born: |  
   | Died: |  |  |  
   | Notes: |  
   | Di Felice has 'Karu, Aivi' in the Tartu Club Jubilee tournament in 1935. Chessgames.com also has a game between Aivi Karu and Keres in Tartu in 1935, as well as correpondence games against Keres. Aivi Karu is a woman chess player, active in Estonia in 1997. A search of Estonian newspapers of the period 1920-1950 for 'Aivi Karu' finds nothing. However, Eesti Maleelu of 1 Jun. 2016 (p.11) lists Arnold Karu in the tournament at Narva in 1928-1929, and an Arnold Karu edited a chess column in Päewaleht at least from the 31 Aug. 1925 issue (p.5), and won a tournament in 1943, according to Postimees of 15 Jan. 1943 (p.2). I am guessing that Di Felice and chessgames.com have this wrong. |  |  |  |  
   | References |  | 
| Books |  
   | Di Felice, Chess Results, 1931-1935, page 332 |  | Periodicals |  
   | [EM], vol. 3, no. 2, 1 June 2016, page 11 |  
   | [Pae], vol. 20, no. 234, 31 Aug. 1925, page 5 |  
   | [Pos], vol. 87, no. 11, 15 Jan. 1943, page 2 |  | Web |  
   | [Aivi Karu] |  |  |