In my 1918 research, I found that over the course of two games, on June 16-17, 1918, the St. Louis Browns intentionally walked Red Sox slugger Babe Ruth in five straight plate appearances:
Sunday, June 16 at St. Louis
4th: StL 1-0, man on 2nd, 2 outs. Ruth BBI, next batter pops out.
6th: StL 1-0, man on 3rd, 2 outs. Ruth BBI, runner caught off 3rd on botched double steal attempt.
8th: Tied 1-1, man on 2nd, 2 outs. Ruth BBI, next batter grounds out 4-3.
Monday, June 17 at St. Louis
1st: Tied 0-0, man on 2nd, 2 outs. Ruth BBI, Sox score 3 runs.
2nd: Sox 3-0, Ruth was the 5th batter in this inning and was BBI, but the play-by-play was not reported.
(In the 8th, with Boston leading 6-0, Ruth came up with 2 outs and runners on 1st and 2nd. The St. Louis was cheering for Ruth to hit and the Browns decided to pitch to him. He drilled a low pitch off the wall in right center for 2 more runs. Sox won 8-0.)
I figured these five BBI were the record at that time -- no batter inspired that much fear. As I was finishing up work on the SABR 1918 book, I wanted to find out if it might still be the record.
I emailed David Smith of Retrosheet fame, and he was kind enough to help. Because of the lack of play-by-play accounts for many games in the first half of the 1900s, Smith said he could answer with any certainty only as far back as 1957.
5 Consecutive BBI
Barry Bonds, September 22-23, 2004
4 Consecutive BBI
Roger Maris, May 22, 1962
Bob Boone, August 19-20, 1980
Barry Bonds, June 29-30, 2002
Barry Bonds, April 23-24, 2004
Barry Bonds, May 1, 2004
Barry Bonds, June 12, 2004
It's not a big surprise to see Bonds's name so often, especially since he walked 198 times in 2002 and 232 (!) times in 2004. Before I heard back from Smith, I found online that Bonds had walked in seven straight plate appearances at some point, but I couldn't tell when that happened or how many of the walks had been intentional. Perhaps his string of 5 BBI was part of that streak.
It turns out it wasn't. Smith said the 5 BBI were part of a six-walk streak, not seven. Smith added that Bonds had tripled both before and after the six straight walks.
A few hours later Smith wrote back to say that he searched for the seven straight walks and found them: September 24-26, 2004 -- almost immediately after the streak of six straight walks!
That sent me off to Retrosheet for the play-by play of those games:
September 22, 2004 v Houston
1st: 2nd, 2 outs - (cb) Triple, RBI
3rd: 2nd, 2 outs - BBI
5th: 2nd, 2 outs - BBI
6th: 1st/2nd, 2 outs - BBI
8th: 2nd, 2 outs - BBI
September 23, 2004 v Los Angeles
1st: 2nd, 2 outs - BBI
3rd: empty, 1 out - (bbcb) BB
5th: empty, 2 outs - (bb) Triple
7th: empty, 2 outs - (fb) L9
September 24, 2004 v Los Angeles
2nd: leadoff - (c) Home Run
4th: empty, 1 out - (fcbbb) Strikeout looking
7th: leadoff - (bcf) Strikeout swinging
9th: 1st, 2 outs - BBI*
September 25, 2004 v Los Angeles
1st: 1st, 2 outs - BBI
3rd: empty, 2 outs - BBI
5th: 1st, 0 outs - (bfbb) BB
7th: 1st, 1 out - BBI
8th: empty, 2 outs (bfsbfb) BB
September 26, 2004 v Los Angeles
1st: empty, 1 out - (bfbb) BB
3rd: empty, 1 out - (b) Home Run
5th: leadoff - (cbbcbf) Strikeout swinging
7th: 1st, 0 outs - (fb) Reached on E4
9th: empty, 2 outs - (sbsf) Infield Single
*:(LA was up 3-2, this pushed tying run to 2nd; next batter walked, loading bases, then a line out to LF ended the game)
There is a good chance that Ruth and Bonds share the major league record with five consecutive intentional walks, although it is possible that someone may unearth evidence that Ruth, Ted Williams or some other great hitter was passed six times in a row.